Passively cooled container system and method

ABSTRACT

A container system may comprise a container, a refrigerant tray, and refrigerant. The container may have a container interior. The refrigerant tray may be mountable within the container interior and may include a sublimation port. The refrigerant may be mounted within the refrigerant tray. The refrigerant may produce a cold gas upon sublimation of the refrigerant. The cold gas may pass through the sublimation port and enter into the container interior.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation-in-part of and claims priorityto pending U.S. patent application Ser. No. 12/778,096 entitledREFRIGERATED CONTAINER filed on May 11, 2010, the entire contents ofwhich is incorporated by reference herein.

STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT

(Not Applicable)

FIELD

The present disclosure relates generally to galley systems and, moreparticularly, to a container for refrigerating items such as airlinemeals prior to distribution to passengers.

BACKGROUND

Aircraft galley carts are used to store food items such as airline mealsfor distribution to passengers by flight attendants. Airline meals aretypically prepared offsite by a caterer who then delivers the meals tothe aircraft just prior to departure. Airline operators are required tomaintain food items at a safe temperature prior to distribution topassengers. For certain long-haul flights, the food items must becontinuously maintained at relatively low temperatures (e.g., below 4degrees Celsius) for extended periods of time such as up to 15 hours orlonger as required by certain agencies.

Airline operators typically use one of several methods for maintainingthe food items within the galley carts below a required minimumtemperature. For example, the galley carts may be cooled by one or moregalley chillers located in the galley area of the aircraft cabin. Eachgalley chiller produces cooled air which may be passed over and aroundthe exterior of the galley cart to maintain the interior below apredetermined temperature. Alternatively, each one of the galley cartsmay be directly connected to an external duct or plenum in the galleyarea such that cooled air from the chiller unit is passed from the ductor plenum directly through the interior of the galley cart.

Although generally effective for their intended purposes, galleychillers possess certain drawbacks which detract from their overallutility. For example, each one of the galley chillers includes an activemechanical refrigeration unit for producing cooled air to be passed overor passed through each galley cart. The mechanical refrigeration unitsadd to the overall weight of the aircraft reducing payload capacity andincreasing fuel consumption. In addition, mechanical refrigeration unitstypically produce noise that adds to aircraft cabin noise and reducespassenger comfort. A further drawback associated with conventionalgalley chillers is that the refrigeration units and associated ductingoccupy valuable space in the galleys which reduces the total amount ofcabin area available for passenger seating

Additional drawbacks associated with conventional galley chillersinclude relatively high manufacturing and installation costs due to thecomplexity of the mechanical refrigeration units. Furthermore, themechanical refrigeration units typically require routine maintenance atregular service intervals which adds to the operating costs of theaircraft. In addition, the mechanical refrigeration units may consumesignificant amounts of electrical power which must be provided by theaircraft power system. For example, a single conventional galley chillerinstalled in an aircraft may draw approximately 4 kilowatts of powerfrom the aircraft power system. To accommodate the power requirements,the galley chiller may require heavy gauge electrical feeder lines andassociated circuit breakers, all of which adds to the weight and spacerequirements of the aircraft.

As can be seen, there exists a need in the art for a system and methodfor maintaining food items on an aircraft below a desired temperaturefor extended periods of time and which eliminates the need for galleychillers and their associated mechanical refrigeration units, electricalfeeder lines and other hardware. In this regard, there exists a need inthe art for a galley cart capable of maintaining the cart interior at arelatively low temperature for extended durations and which is low incost, simple in construction and which occupies a minimal amount ofcabin space.

BRIEF SUMMARY

The above-noted needs associated with galley carts are specificallyaddressed and alleviated by the present disclosure which, in anembodiment, provides a cold tray that may be installed within aninterior of a container. In an embodiment, the container may beconfigured as a galley cart although the container may be provided inany one of a variety of different configurations which may beimplemented in any vehicular or non-vehicular application for use in anyindustry. The cold tray may comprise a substantially hollow cold trayhousing which may be removably mounted within the interior of thecontainer. The cold tray housing may contain a refrigerant and may befluidly connectable to an air flow source which may draw air from thecontainer interior into the cold tray housing such that the air passesover the refrigerant causing the air to be cooled. The cooled air maythen be discharged back into the container interior.

In a further embodiment, the present disclosure includes a containersystem which may comprise a container having a container interior suchas for storing food or other items. The container may include a coldtray that may be mounted within the container interior. The cold traymay include a refrigerant. The container system may further include anair flow source for drawing air from the container interior into thecold tray such that the air passes over the refrigerant and is directedback into the container interior.

In a further embodiment, the present disclosure includes a method ofrefrigerating an interior of a container. The method may comprise thestep of mounting a cold tray within the interior of the container. Thecold tray may include a refrigerant. The method may further include thestep of drawing air from the container interior into the cold tray suchthat the air passes over the refrigerant. The method may furthercomprise discharging the air from the cold tray back into the containerinterior.

Also disclosed is a passively cooled container system which may comprisea container, a refrigerant tray, and refrigerant. The container may havea container interior. The refrigerant tray may be mountable within thecontainer interior and may include a sublimation port. The refrigerantmay be mounted within the refrigerant tray. The refrigerant may producea cold gas upon sublimation of the refrigerant. The cold gas may passthrough the sublimation port and enter into the container interior.

In a further embodiment, disclosed is an aircraft which may include apassively-cooled movable container and at least one refrigerant tray.The container may include a container interior and may be configured tocontain a plurality of food trays. The container may be formed of aplurality of vacuum insulated panels enclosing the container interior.The refrigerant tray may contain refrigerant and may be mounted withinthe container interior above at least one of the food trays. Therefrigerant tray and the container may be configured to cooperativelymaintain the air temperature within the container interior at less thanapproximately 4° C. for a period of at least approximately 15 hours inan environment having an ambient air temperature of greater thanapproximately 29° C.

Also disclosed is a method of refrigerating an interior of a container.The method may include the step of mounting a refrigerant tray withinthe container interior. The refrigerant tray may have a sublimation portand may contain a refrigerant. The method may additionally include thestep of sublimating the refrigerant to produce a cold gas. The methodmay also include the step of passing the cold gas through thesublimation port and into the container interior for cooling thereof.

The features, functions and advantages that have been discussed can beachieved independently in various embodiments of the present disclosureor may be combined in yet other embodiments, further details of whichcan be seen with reference to the following description and drawingsbelow.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features of the present disclosure will become moreapparent upon reference to the drawings wherein like numerals refer tolike parts throughout and wherein:

FIG. 1 is a perspective illustration of a container system in anembodiment;

FIG. 2 is a perspective illustration of the container system in anembodiment comprising a container configured as an insulated galley cartand including a cold tray which is mountable within a container interiorof the galley cart;

FIG. 3 is a perspective illustration of the container system in anembodiment having a fan module that may be separately mounted to thecontainer and fluidly connected to the cold tray;

FIG. 4 is a perspective illustration of the container system in anembodiment wherein the fan module is integrated into the container body;

FIG. 5 is a perspective illustration of the container systemillustrating the cold tray positioned at an approximate mid-height ofthe container interior and further illustrating a plurality of foodtrays mounted on tray supports within the container interior;

FIG. 6 is a side view of the galley cart illustrating counter rotatingupper and lower airflow circuits generated by an air flow sourcecomprising at least one circulation fan;

FIG. 7 is a top perspective illustration of the container system havinga side wall removed to illustrate the flow of air between the foodtrays;

FIG. 8 is a bottom perspective illustration of the galley cartillustrating air discharged by upper and lower fans and formingrespective upper and lower airflow circuits;

FIG. 9 is a top sectional illustration of the container system takenalong line 9-9 of FIG. 6 and illustrating an embodiment of the foodtrays having scallops formed along perimeter lips of the food trays toprovide food tray air gaps;

FIG. 10 is a perspective illustration of an embodiment of the food trayhaving scallops formed along the perimeter lips of the food tray;

FIG. 11 is a top perspective illustration of the container interiorillustrating a plurality of the food trays having scallops on theperimeter lips and further illustrating the flow of air through the foodtray air gaps collectively formed by the scallops of adjacent foodtrays;

FIG. 12 is a sectional illustration of the galley cart taken along line12-12 of FIG. 9 and illustrating the cold tray mounted to a pair of traysupports engaging longitudinal recesses formed on lateral sides of thecold tray;

FIG. 13 is a perspective illustration of a vacuum insulated panel fromwhich the container body may be constructed;

FIG. 14 is a top sectional view of the galley cart illustrating anembodiment of the food trays having a plurality of vent holes formed inthe perimeter lips to facilitate the flow of air between layers of thefood trays;

FIG. 15 is a perspective illustration of the embodiment of the food trayhaving the vent holes;

FIG. 16 is a perspective illustration of the container interiorillustrating a plurality of the food trays having the vent holes;

FIG. 17 is a top perspective illustration of an embodiment of the coldtray having a front end having at least one circulation fan and a backend having a cold tray air inlet;

FIG. 18 is a bottom perspective illustration of the front end of thecold tray;

FIG. 19 is an aft perspective illustration of an aft end of the coldtray and illustrating an end frame forming the cold tray air inlet;

FIG. 20 is a top perspective illustration of a fan module that may beconfigured as a separate unit from the cold tray;

FIG. 21 is a perspective illustration of the container system in anembodiment having a battery pack that is detachably mounted to thecontainer body;

FIG. 22 is a perspective illustration of the cold tray in an embodimenthaving a plurality of cold packs containing refrigerant;

FIG. 23 is a cross-sectional illustration of the cold tray taken alongline 23-23 of FIG. 22 and illustrating the refrigerant contained withinone of the cold packs;

FIG. 24 is a side sectional illustration of the cold tray taken alongline 24-24 of FIG. 22 and illustrating the plurality of cold packshoused within the cold tray housing and further illustrating the endframe pivoted downwardly to allow for removal of the cold packs from thecold tray housing;

FIG. 25 is a top view of a fan compartment of the cold tray includingthe upper and lower fans;

FIG. 26 is a sectional illustration of the cold tray taken along line26-26 of FIG. 25 and illustrating the flow of air from the cold trayhousing toward the upper and lower fans prior to discharge of the airfrom upper and lower fan outlets;

FIG. 27 is a perspective illustration of the cold tray and a cold packhaving a generally streamlined shape;

FIG. 28 is a sectional illustration of the cold tray taken along line28-28 of FIG. 27 and illustrating refrigerant contained within the coldpack and further illustrating a cold pack air channel formed between thecold tray housing and the cold pack;

FIG. 29 is a top view of the cold tray taken along line 29-29 of FIG. 27and illustrating the cold pack housed within the cold tray housing;

FIG. 30 is a side sectional illustration of the cold tray taken alongline 30-30 of FIG. 25 and illustrating the flow of air from thecontainer interior into the cold tray air inlet and along the cold trayhousing prior to discharge by the upper and lower fans;

FIG. 31 is a side view of a galley area of an aircraft illustratinginsertion of one of the galley carts into a cart storage slot;

FIG. 32 is a top view of the galley area illustrating the insertion ofone of the galley carts into one of the cart storage slots of a galleystructure;

FIG. 33 is a perspective illustration of the galley cart stored in oneof the galley storage slots and further illustrating an inductivecharging system for charging a battery pack;

FIG. 34 is a top sectional illustration of a portion of the galley cartand the galley structure housing the galley cart and illustratinginductive charging of the battery pack;

FIG. 35 is a top sectional illustration of an embodiment having an airsupply fluidly connected to a turbine that is coupled to the circulationfan mounted within the fan module of the galley cart;

FIG. 36 is a side sectional illustration of the galley cart and galleystructure taken alone line 36-36 of FIG. 35 and illustrating theinterconnection of the air supply to the circulation fan;

FIG. 37 is an illustration of a graph comparing the latent heats of dryice and water ice;

FIG. 38 is an illustration of a graph plotting quantity of refrigerantversus elapsed time for galley cart configurations having differentR-values;

FIG. 39 is an illustration of a graph plotting air temperature of thecontainer interior versus elapsed time and comparing configurations ofthe galley cart having similar R-values and containing differentquantities and types of refrigerant;

FIG. 40 is a flow chart illustrating a method of operating a galleycart;

FIG. 41 is a flow chart of an embodiment of a method including one ormore operations that may be performed in refrigerating the interior of acontainer;

FIG. 42 is a perspective illustration of the container system in anembodiment including a refrigerant tray that may be mountable within thecontainer interior;

FIG. 43 is a perspective illustration of the container system showingthe refrigerant tray mounted within the container interior;

FIG. 44 is a bottom perspective illustration of an embodiment of therefrigerant tray having a pair of sublimation ports formed in therefrigerant tray;

FIG. 45 is a top perspective illustration of the refrigerant tray havinga pair of tray vents;

FIG. 46 is a cross section view of the refrigerant tray taken along line46 of FIG. 45 and illustrating a refrigerant such as dry ice mounted ona thermal isolator within the refrigerant tray;

FIG. 47 is a perspective illustration of the container system in anembodiment including a refrigerant tray having a tray chamfer formounting within a cart having a container chamfer for controlling theorientation of the refrigerant tray within the container interior;

FIG. 48 is a perspective illustration of the container system showingthe refrigerant tray of FIG. 47 installed in the container and the traychamfer nesting within a container chamfer;

FIG. 49 is a sectional view of the container taken along line 49 of FIG.47 and illustrating a stopper mechanism mounted to the containerinterior for controlling the depth of installation of the refrigeranttray within the container interior;

FIG. 50 is an exploded perspective illustration of the refrigerant trayhaving a thermal regulator mounted between the refrigerant and thethermal isolator;

FIG. 51 is a cross sectional view of the refrigerant tray illustrated inFIG. 47;

FIG. 52 is a bottom perspective view of the refrigerant tray illustratedin FIG. 47 and showing the sublimation ports located at corners of therefrigerant tray;

FIG. 53 is a perspective illustration of the container system having aspacer device mounted on an interior surface of a cart door formaintaining an air gap between food trays and the cargo door and furtherillustrating cold gas exiting the sublimation ports and passing throughthe air gaps;

FIG. 54 is a side view of the container system illustrating the cold gasexiting the sublimation ports and flowing along sublimation paths withinthe container interior;

FIG. 55 is a sectional top view of the container system taken along line55 of FIG. 54 and illustrating the air gap between the food trays andthe interior surface of the cart door;

FIG. 56 is a perspective illustration of the container system showingthe interior surface of the container side walls having a plurality ofsupport knobs for supporting the food trays and/or refrigerant trays andfurther illustrating an embodiment of the mid-shelf having a pluralityof shelf scallops to facilitate the passage of cold gas and/or air;

FIG. 57 is a sectional top view of the container system taken along line57 of FIG. 56 and illustrating side gaps between the food trays and theinterior surface of the side walls;

FIG. 58 is a cross section view of a portion of the container systemtaken along line 58 of FIG. 57 and illustrating one of the food trayssupported on a support knob;

FIG. 59 is a side view of the container system having refrigerant traysformed without openings as shown in FIG. 60 and illustrating cold aircooled by contact with the refrigerant trays and sinking within thecontainer to displace warm air and cause the rising of the warm airtoward the dry icy trays;

FIG. 60 is a is a bottom perspective illustration of an embodiment ofthe refrigerant tray lacking openings or sublimation ports;

FIG. 61 is a perspective illustration of a further embodiment of thecontainer system with the cart door in a closed position;

FIG. 62 is a perspective illustration of an inner shell of the containerand a plurality of stiffener rings that may be mounted to the innershell;

FIG. 63 is a partially exploded perspective illustration of a pluralityof vacuum insulated panels for mounting to the inner shell;

FIG. 64 is an exploded perspective illustration of a plurality of shellsections that may be assembled to form an outer shell of the container;

FIG. 65 is a perspective illustration of the outer shell assembled tothe vacuum insulated panels and the inner shell;

FIG. 66 is an illustration of a joint of two longitudinal flanges havingC clips installed thereon;

FIG. 67 is a cross sectional illustration of an interface of the cartdoor with a door frame of the container;

FIG. 68 is a perspective illustration of a further embodiment of thecontainer that may be assembled using edging;

FIG. 69 is an exploded perspective illustration of an upper portion ofthe container of FIG. 68 and illustrating the interconnection of the topwall to the side walls using caps and edging;

FIG. 70 is an exploded perspective illustration of a lower portion ofthe container of FIG. 68 and illustrating the interconnection of thebottom wall to the side walls using caps and edging;

FIG. 71 is a cross sectional illustration of an interface of the cartdoor disposed in overlapping relation to the side wall of the container;

FIG. 72 is a cross sectional illustration of the side wall showing across bar mounted within the side wall for attaching a mid shelf to theside wall; and

FIG. 73 is a flow chart of an embodiment of a method including one ormore operations that may be performed for cooling the interior of thecontainer using the refrigerant tray.

DETAILED DESCRIPTION

Referring now to the drawings wherein the showings are for purposes ofillustrating preferred and various embodiments of the disclosure, shownin FIGS. 1-8 is a container system 10 as may be used in an aircraftcabin. The container system 10 may comprise an insulated galley cart 12housing a cold tray 80 (FIG. 2) containing refrigerant (FIG. 2). Thecold tray 80 is insertable within a container interior 42 of the galleycart 12 for maintaining food or other items stored within the galleycart 12 at a safe temperature. The cold tray 80 comprises aself-contained cooling unit that, when installed within the galley cart12, may maintain the air temperature of the container interior 42 belowa desired temperature. For example the cold tray 80 may maintain thecontainer interior 42 at between approximately 0° C. and approximately7° C. for extended durations of up to 15 hours or longer. However, thegalley cart 12 and the cold tray 80 may be configured to maintain theair temperature of the container interior 42 at temperatures below 0° C.In this regard, the refrigeration capabilities of the container system10 may be dependent in part upon the cooling capacity of the cold tray80 and the insulative properties of the container body 14 as describedin greater detail below.

Referring briefly to FIG. 23, the cold tray 80, in an embodiment, maycomprise a generally hollow member for containing refrigerant 188. Therefrigerant 188 may comprise a phase change material 190 which mayundergo a phase change to absorb heat from the air in proximity to therefrigerant 188. In an embodiment, the cold tray 80 may be fluidlycoupled or connected to an air flow source 132 such as a fan module 134having one or more circulation fans 140 such an upper fan 142 and alower fan 152. For example, as illustrated in FIG. 2, the cold tray 80and fan module 134 may be integrated into an assembly that may beremovably mounted in the container interior 42.

Referring to FIG. 3, in an alternative embodiment, the fan module 134may comprise a separate assembly that may be mounted within thecontainer interior 42 as a standalone unit. The fan module 134 may befluidly coupled to the cold tray 80. The cold tray 80 may be providedwith an opening that fluidly communicates with the fan module 134. Whenthe fan module 134 is activated, air may be drawn through the cold trayhousing 82 such that the air passes over the refrigerant 188 under theinfluence of a circulation fan 140 in the fan module 134. The air maythen be discharged back into the container interior 42 for cooling thecontents of the container 11.

Referring to FIG. 4, in a further non-limiting embodiment, the fanmodule 134 may be integrated into the container 11. For example, the fanmodule 134 may be fixedly mounted or integrated into side walls 16and/or end walls 18 of the container interior 42 as shown in FIG. 4. Thecold tray 80 may be installed within the container interior 42 and maybe fluidly coupled to the fan module 134. Upon activation of thecirculation fan 140, air may be drawn into the cold tray housing 82 suchthat the air flows past the refrigerant 188 causing the air to be cooledprior to discharge back into the container interior 42. Although FIG. 4illustrates the fan module 134 as being mounted adjacent to one end ofthe container interior 42, the fan module 134 may be installed at anyhorizontal or vertical location within the container interior 42.Furthermore, the fan module 134 may be provided in any size, shape andconfiguration and is not limited to that which is shown in FIGS. 2-4.For example, the fan module 134 may be integrated into one or more ofthe side walls 16, end walls 18 and/or top and bottom walls 30, 32 thatmake up the container body 14. Even further, the fan module 134 may beintegrated into an interior and/or an exterior of the side walls 16, endwalls 18 or top and bottom walls 30, 32 of the container body 14.

Referring to FIGS. 2-4, the cold tray 80 may be fluidly connectable toany suitable air flow source 132 such as the above-described fan module134 for drawing air from the container interior 42 into the cold trayhousing 82. For example, as indicated above, the fan module 134 maycomprise at least one air circulation fan 140 that may be mounted to orwithin the fan module 134 although the circulation fan 140 may bemounted to the cold tray 80, the container 11 or any combinationthereof. The fan module 134 may draw air into the cold tray housing 82and discharge cooled air back into the container interior 42 as bestillustrated in FIGS. 6-7. In this regard, the circulation fan 140 maydraw air from the container interior 42 into a cold tray air inlet 84formed on an end of the cold tray 80. As indicated above, the cold tray80 may be configured such that the air that is drawn into the cold trayair inlet 84 passes over the refrigerant 188 causing the air to cool asthe air flows through the cold tray housing 82 from the back end 88toward the front end 86 of the cold tray 80.

Referring to FIG. 2, the container system 10 may be configured to allowfor the selective mounting of the cold tray 80 and the fan module 134 atany vertical location within the container interior 42. In this manner,the container system 10 may facilitate a substantially uniformtemperature distribution within the container interior 42. In anembodiment, the cold tray 80 may be installed at an approximatemid-height 110 of the container interior 42 as illustrated in FIG. 2.The cold tray 80 essentially divides the interior volume of thecontainer interior 42 into upper and lower portions 52, 54 as shown inFIG. 6.

Referring to FIG. 6, in an embodiment, the air flow source 132 mayinclude the circulation fan 140 which may comprise upper and lower fans142, 152 for discharging cooled air into respective ones of the upperand lower airflow circuits 106, 108. Air discharged by the upper fan 142establishes the upper airflow circuit 106 as best seen in FIG. 6.Likewise, air discharged by the lower fan 152 establishes the lowerairflow circuit 108. Although the embodiment of the cold tray 80disclosed herein includes upper and lower fans 142, 152, any number ofcirculation fans 140 may be provided for discharging air in anydirection within the container interior 42.

Referring briefly to FIG. 22, an embodiment of the cold tray 80 mayinclude a logic circuit 172 which may be communicatively coupled to oneor more thermostats 176 and/or temperature sensors 174 to sense the airtemperature of the container interior 42 or the temperature of the foodor other items within the container interior 42 and activate the upperand lower fans 142, 152 in order to maintain the air temperature withinthe container interior 42 at or below a desired value. Toward this end,an embodiment of the cold tray 80 may further include a power source 164such as a battery pack 166 which may be disposed within or mounted tothe cold tray 80 for powering the upper and/or lower fans 142, 152 on anas-needed basis in response to signals provided by the logic circuit172. Alternatively, the upper and lower fans 142, 152 may be activatedaccording to a preprogrammed operating schedule. The upper and lowerfans 142, 152 may also be manually activated. The upper and lower fans142, 152 are preferably activated such that the air temperature of thecontainer interior 42 may be maintained at a substantially uniformtemperature.

In an embodiment, the battery pack 166 may be configured to bereplaceable and/or rechargeable. For example, the fan module 134 mayinclude an access panel 170 as best seen in FIG. 22 to allow access tothe battery pack 166. Alternatively, the battery pack 166 may be mountedto an exterior of the container 11 such as to one of the cart doors 20as illustrated in FIG. 21. However, the battery pack 166 may be mountedat any suitable location on the interior or exterior of the container 11or at any location on the fan module 134 or cold tray 80. By includingthe battery pack 166, the cold tray 80 may eliminate the need forexternal power such as from an aircraft power system. However, it iscontemplated that the container system 10 may be coupled to an externalpower source such as by direct or indirect (e.g., wireless) connectionfor powering of the upper and lower fans 142, 152.

Referring briefly to FIGS. 5-6, in an embodiment, the upper and lowerportions 52, 54 of the interior may be maintained at differenttemperatures. For example, the upper portion 52 may contain items suchas perishables that require refrigeration at 7° C. or below such as atless than 4° C. The lower portion 54 may contain items such asnon-perishables that tolerate a relatively higher refrigerationtemperature such as 12° C. The upper and lower portions 52, 54 may bemaintained at different temperatures by operating the fans 142, 152 toprovide differential amounts and/or temperatures of cooled air into therespective upper and lower portions 52, 54. For example, the lower fan154 may be operated on a more frequent basis and/or for extendeddurations such that a relatively greater amount of cooled air iscirculated into the lower airflow circuit 108 (FIG. 6) as compared tothe amount of cooled air that is circulated into the upper airflowcircuit 106 (FIG. 6). In addition, the cold tray 80 may be positionedwithin the container interior 42 to create a relatively small volume ofthe lower portion 54 relative to the volume of the upper portion 52 as ameans to reduce the amount of heat exchange required to maintain thelower portion 54 at a colder temperature relative to the upper portion52.

Referring more particularly now to FIG. 1, shown is a perspectiveillustration of the galley cart 12 in a configuration as may be used inthe context of an aircraft cabin for meal services. It should be notedthat the container system 10 as disclosed herein may be applied to avariety of different industries and is not limited to airlineoperations. In this regard, the galley cart 12 and cold tray 80 may beimplemented in any vehicular or non-vehicular application requiringrefrigeration of food items. Furthermore, the container system 10 asdisclosed herein is not limited to refrigeration of food items but maybe extended for use in refrigerating any type of non-food items.

Referring still to FIG. 1, the galley cart 12 is illustrated as having aphysical box-like envelope commonly associated with commercial airlineroperations. However, the galley cart 12 may have any one of a variety ofdifferent sizes, shapes and configurations and is not limited to thegenerally rectangular box-like shape illustrated in FIG. 1. In theembodiment illustrated in FIG. 1, the container body 14 may comprise apair of opposing side walls 16 joined on the ends by a pair of opposingcart doors 20 (FIG. 2). The cart doors 20 may each be independentlypivotable to expose the container interior 42. However, the galley cart12 may include non-movable end walls 18 (FIG. 1) mounted on one of theopposing ends of the galley cart 12 as an alternative to the double cartdoor 20 configuration of the container system 10 shown in FIG. 2.

As can be seen in FIG. 1, the cart may include a top wall 30 and abottom wall 32 for enclosing the container interior 42. In anembodiment, the galley cart 12 may include one or more hand rails 56such as the pair of hand rails 56 mounted on opposing ends of the galleycart 12 and including an ergonomically-shaped grip portion 58 formedwith the hand rails 56. The top wall 30 may include a rim 60 such thatthe top wall 30 defines a recess portion 62. The galley cart 12 mayinclude a plurality of wheels or casters 64 for transporting the galleycart 12. As can be seen in FIGS. 1-2, each one of the cart doors 20 maybe pivotally mounted to the cart side walls 16 by one or more hinges 22.In addition, the cart door 20 may include a door latch 24 for latchingthe cart door 20 to the container body 14. The cart door 20 maypreferably include a door seal 26 which may extend around a perimeter ofthe cart door 20 for sealing the cart door 20 to the side walls 16 andtop and bottom walls 30, 32 of the container body 14.

The container body 14 is preferably constructed to thermally insulatethe container interior 42 and minimize heat exchange between thecontainer interior 42 and the external environment. In this regard, theside walls 16, cart doors 20 and top and bottom walls 30, 32 maypreferably, but optionally, be formed of any suitable insulatingconstruction including, but not limited to, the use of insulated panelssuch as vacuum insulated panels 34 as described in greater detail below.In this manner, the container body 14 may provide a relatively highthermally insulative capability to limit heat gain within the containerinterior 42. For example, an embodiment of the container system 10 maybe configured such that the galley cart 12 may limit heat gain in thecontainer interior 42 to less than approximately 2000 Btu/hour in anenvironment having an ambient temperature of higher than approximately29° C. and, more preferably, less than approximately 100 Btu/hour in anenvironment having an ambient temperature of higher than approximately29° C. The insulative capability of the container body 14 may be definedas the collective thermal resistance of the side walls 16, cart doors20, and top and bottom walls 16, 30, 32 that make up the container body14. In an embodiment, the container body 14 may have an overalleffective R-value of approximately 15 depending upon the door seal 26configuration and the construction of the side, top and bottom walls 30,32 and cart doors 20 that make up the container body 14. However, thegalley cart 12 may be configured to limit heat gain in the containerinterior 42 to any desired value in relation to the ambient temperatureof the external environment.

Referring more particularly now to FIG. 2, shown is the container system10 illustrating each one of the cart doors 20 pivoted into an openposition and exposing the cold tray 80. The cold tray 80 is illustratedas being partially installed within the container interior 42. Althougha single cold tray 80 is illustrated in FIG. 2, any number may beprovided and at any location. For example, although FIG. 2 illustratesthe cold tray 80 installed at an approximate mid-height 110 of thecontainer interior 42, it is contemplated that a pair of cold trays 80may be selectively positioned at any vertical location within thecontainer interior 42 to provide the desired level of cooling of thecontents of the container interior 42. Furthermore, the cold tray 80 maybe selectively positioned at a location within the container interior 42to provide a desired temperature distribution along the vertical heightof the container interior 42.

For items such as food products (e.g., ice cream) that must remainfrozen (i.e., below 0° C.), it may be desirable to mount the food tray120 containing such items immediately adjacent to the cold tray 80. Forexample, referring briefly to FIG. 12, shown is a cross-sectionalillustration of the cold tray 80 mounted to the container body 14 andillustrating a food tray 120 mounted in substantially direct contactingrelation to the cold tray 80 such that heat may be conductivelytransmitted between the cold tray housing 82 and the food tray 120 tomaintain the temperature of items on the food tray 120 at a relativelycolder temperature relative to the food trays 120 that are mounted innon-contacting relation to the cold tray 80.

Referring to FIG. 2, shown are a plurality of vertically-spaced traysupports 48 or support rails 50 which may be used for supporting thefood trays 120 and cold tray 80 at any vertical location within thecontainer interior 42. The cold tray 80 may include one or moremechanisms for engaging or receiving the tray supports 48. For example,as shown in FIG. 12, the cold tray 80 may include a longitudinal recess92 that may extend generally longitudinally along each one of thelateral sides 90 of the cold tray 80 for engaging tray supports 48. Thetray supports 48 may be mounted to or integrated with the side walls 16.The tray supports 48 may be sized and configured complementary to thelongitudinal recesses 92 of the cold tray 80. Although FIG. 12illustrates the tray supports 48 for the cold tray 80 as having a largercross section that the tray supports 48 for the food trays 120, all ofthe tray supports 48 may be substantially identically configured. Inthis manner, the longitudinal recesses 92 may be sized and configured tobe mountable on the same tray supports 48 that are used for supportingthe food trays 120.

As shown in FIG. 5, the tray supports 48 may be configured as generallylongitudinally extending support rails 50 which may be vertically-spacedrelative to one another at substantially equivalent spacings in avertical direction. In this regard, the configuration of the traysupports 48 illustrated in FIG. 2 is a non-limiting example of any oneof a variety of different tray support 48 configurations that may beused for supporting the cold tray 80 and/or the food trays 120 at anylocation within the container interior 42. However, the tray supports 48may be configured to be mounted to the side walls 16 in a non-uniformspacing. For example, the tray supports 48 may be mounted such that atleast one layer of food trays 120 is mounted in close proximity toand/or in substantially direct contact with the cold tray 80 tofacilitate heat conduction to the food tray 120 for improved cooling ofthe contents of the food tray 120. It should further be noted that thetray supports 48 are not limited to the embodiment of the support rails50 illustrated in FIG. 2 but may be provided in any configurationincluding, but not limited to, discrete bosses, extensions, hooks,slots, recesses or any other suitable feature which may be mounted inany manner at any location within the container interior 42.

Referring to FIGS. 1, 5 and 21, the cold tray 80, container body 14and/or battery pack 166 may include a battery status indicator 168 forindicating the status of the power source 164 such as the battery pack166 illustrated in FIG. 22\. The battery pack 166 may provide power tothe upper and lower fans 142, 152 as indicated above. The battery statusindicator 168 may provide an indication of a relatively low level ofpower remaining in the battery pack 166. Alternatively, the batterystatus indicator 168 may continuously indicate the level of availablepower such that the battery pack 166 may be replaced or recharged asnecessary. The battery status indicator 168 may be mounted at anysuitable location on the cold tray 80 including on an end thereof asillustrated in FIG. 2. The battery status indicator 168 may be mountedon an exterior of the cart door 20 as illustrated in FIG. 1 in order toprovide a visual and/or auditory signal representative of the amount ofavailable power in the battery pack 166. The battery pack 166 may alsobe externally mounted to the container body 14 such as to the cart door20 as shown in FIG. 21 or to any other location on the container body14.

In the embodiment illustrated in FIG. 22, the fan module 134 mayadvantageously be configured to provide convenient access to the batterypack 166 such as by removing an access panel 170. Alternatively, thebattery pack 166 may be exteriorly accessible without removal of anaccess panel 170. For example, the battery pack 166 may be mounted to anexterior of the fan module 134 or at any location on the container 11exterior such as to the cart door.

Referring back to FIG. 2, the cold tray 80 may optionally include a doorsensor 28 mounted on the cold tray 80 such as at an end thereof to sensean open position and/or a closed position of the cart door 20. In anembodiment, upon sensing that the cart door 20 is open, the door sensor28 may send a signal to the logic circuit 172 or power source 164 todeactivate or shut off the flow of power to the upper and/or lower fans142, 152. The battery status indicator 168 may also be configured toprovide a warning signal to indicate to a flight attendant of an opencart door 20.

Referring to FIG. 5, shown is a perspective illustration of thecontainer system 10 and further illustrating the installation of aplurality of individual food trays 120 on the vertically-spaced traysupports 48 mounted to the side walls 16 of the container body 14.Although FIG. 5 illustrates the food trays 120 being mounted on traysupports 48 disposed immediately adjacent to the cold tray 80, it isrecognized that the food trays 120 may be mounted on any one or all ofthe tray supports 48 and at any spacing and is not limited to that whichis illustrated in FIG. 5. Likewise, although the cold tray 80 isillustrated as being mounted on the tray support 48 at an approximatemid-height 110 of the interior, as was earlier mentioned, the cold tray80 may be mounted at any vertical location within the container interior42 in order to achieve a desired temperature profile within thecontainer interior 42.

As can be seen in FIG. 5, each one of the food trays 120 may besupported on the tray supports 48 by means of perimeter lips 122extending around each one of the food trays 120. The support rails 50may be provided with detents (not shown) to engage the perimeter lips122 of each one of the food trays 120 in order to fix each one of thefood trays 120 in a desired longitudinal position (i.e., forward and aftdirection) along the tray supports 48 and to maintain the food trays 120at a desired spacing relative to one another and a desired spacingbetween an end-most one of the food trays 120 and the cart doors 20. Aswill be described in greater detail below, air gaps 128 (FIG. 9) betweeneach one of the food trays 120 and air gaps 130 (FIG. 9) between theend-most food trays 120 and the cart doors 20 may facilitate airflowcirculation within the container interior 42.

Referring to FIG. 6, shown is a side illustration of the containersystem 10 having one of the side walls 16 removed to expose thecontainer interior 42 and illustrate the relative positioning of thecold trays 80 and the food trays 120. As can be seen, the cold tray 80may be configured to discharge cooled air from the cold tray housing 82into respective ones of the upper and lower portions 52, 54 of thecontainer interior 42 such that upper and lower airflow circuits 106,108. As was noted above, the cold tray 80 may be mounted at any verticallocation within the container interior 42. For example, it iscontemplated that the cold tray 80 may be mounted toward an upper end ofthe interior of the container. Although not shown, the cold tray 80 maybe mounted at a location that is adjacent to the top wall 30 of thecontainer such that the cold tray 80 divides the container interior 42into a relatively small volume of the upper portion 52 and a relativelylarge volume of the lower portion 54. Alternatively, the cold tray 80may be mounted immediately adjacent to the top wall 30 such that only alower portion 54 of the container interior 42 is formed.

Likewise, although not shown, the cold tray 80 may be mounted orpositioned toward a lower end of the container interior 42 adjacent tothe bottom wall 32 such that a relatively small volume of the lowerportion 54 and a relatively large volume of the upper portion 52 isformed. Alternatively, the cold tray 80 may be positioned at an extremelower position within the container interior 42 such that only an upperportion 52 of the container interior 42 is formed. As can be seen, thecold tray 80 may be selectively mounted at any vertical location withinthe container interior 42 of the container 42. In addition, the coldtray 80 may be configured to discharge air into the upper and lowerportions 52, 54 at the same rate or at different rates in order tomaintain a desired temperature range within the respective upper andlower portions 52, 54. In this regard, the cold tray 80 may beconfigured to discharge air into the upper and lower portions 52, 54which may optionally be maintained at different temperatures.

Referring to FIGS. 6 and 9, the cold tray 80 may be configured to have alength that facilitates the formation of a cold tray end gap 98 (FIG. 9)between at least one end of the cold tray 80 and a door inner surface 44of the cart door 20. The cold tray end gap 98 as illustrated in FIG. 9may facilitate the entry of air from the container interior 42 into thecold tray air inlet 84 formed on the end of the cold tray 80 as alsoshown in FIG. 30. Although the cold tray 80 is illustrated as having alength that is generally complementary to a length of the containerinterior 42, the cold tray 80 may be provided in a length that isshorter than that which is illustrated in the Figures. Furthermore, thecold tray 80 may be configured as two or more distinct cold trays (notshown) that may be disposed in spaced arrangement relative to oneanother or in end-to-end arrangement relative to one another with eachcold tray having a cold tray air inlet and at least one circulation fan140 for drawing air from the interior into the cold tray air inlet anddischarging cooled air back into the container interior 42. The coldtray 80 may also be configured as a separate assembly from the fanmodule 134 as indicated above

Referring to FIGS. 7-8, shown are perspective illustrations of thecontainer system 10 having the cold tray 80 and food trays 120 mountedwithin the container interior 42 and illustrating the discharge of thecooled air into the upper and lower portions 52, 54 of the containerinterior 42 by means of the upper and lower fans 142, 152. The upper andlower fans 142, 152 may be mounted to the fan module 134 which may beprovided as a standalone unit or integrated into the cold tray housing82. The upper and lower fans 142, 152 may be mounted on an end of thecold tray housing 82 opposite the end having the cold tray air inlet 84.However, it is contemplated that the circulation fans 140 may be mountedat any location along the length of the cold tray 80 and are not limitedto mounting at end of the cold tray 80 opposite the cold tray air inlet84. For example, the cold tray 80 may be include a circulation fan 140on the back end 88 for drawing air into the cold tray air inlet and acirculation fan 140 on the front end 86 for discharging the cooled airback into the container interior 42.

As can be seen in the embodiment illustrated in FIGS. 7 and 8, the upperand lower fans 142, 152 may direct air into respective ones of the upperand lower portions 52, 54 of the container interior 42. The upper fan142 may direct air in a generally upward direction toward the upperportion 52 of the container interior 42 in order to form the upperairflow circuit 106. Likewise, the lower fan 152 may direct air in agenerally downward direction into the lower portion 54 of the containerinterior 42 in order to form the lower airflow circuit 108.

In an embodiment shown in FIGS. 6-8, the container system 10 may beconfigured such that the upper and lower airflow circuits 106, 108 formcounter-rotating flow paths within the container interior 42 wherein theair is passed over the layers of food trays 120 mounted within thecontainer interior 42 from the front end 86 of the cold tray 80 towardthe back end 88 of the cold tray 80 whereupon the air may be drawn intothe cold tray air inlet 84. In this regard, the circulation fans 140 maybe configured to draw the air into the cold tray air inlet 84 such thatthe air passes through the cold tray housing 82 as best seen in FIG. 6.As was earlier indicated, the cold tray housing 82 may containrefrigerant 188 (FIG. 12) such as phase change material 190 (FIG. 12) inorder to cool the air as the air is drawn past the refrigerant 188.

In an embodiment, the refrigerant 188 may be contained within one ormore cold packs 180 (FIG. 20) which may be housed within the cold trayhousing 82. The cold tray housing 82 and the cold pack 180 may beconfigured to provide one or more cold pack air channels 192 as shown inthe non-limiting example of FIG. 28 to illustrate the flow of air pastthe cold pack 180 toward the upper and lower fans 142, 152. As shown inFIG. 6-8, the upper and lower fans 142, 152 discharge the cooled airback into at least one of the upper and lower portions 52, 54 to formthe counter-rotating upper and lower airflow circuits 106, 108.

Referring to FIG. 9, shown is a top sectional illustration of thecontainer interior 42 illustrating a plurality of the food trays 120mounted to the tray supports 48. Although three food trays 120 are shownmounted in end-to-end arrangement on one of the tray supports 48, anynumber of food trays 120 may be provided. In this regard, the food trays120 may be configured in an industry standard configuration. However,the food trays 120 may be configured in any desired size, shape andconfiguration and are not limited to the specific arrangementillustrated in FIG. 9.

Referring to FIG. 7, the food tray 120 is preferably mounted within thecontainer interior 42 to provide a food tray end gap 130 between anend-most one of the food trays 120 and the cart door 20 at the front end86 of the cold tray 80 to facilitate airflow therebetween. In addition,the cold tray 80 may be mounted to provide a cold tray end gap 98 at theback end 88 of the cold tray 80 for the entry of air into the cold trayair inlet 84. At the front end 86, the cold tray 80 may be mounted incloser proximity to the cart door 20 due to a reduced need for air flowbetween the cold tray 80 and the cart door 20 at the front end 86.

Referring briefly to FIG. 10, shown is a perspective illustration of anembodiment of the food tray 120 mounted on the support rails 50 locatedon opposing sides of the container interior 42 along the side walls 16.As can be seen in FIG. 10, the food tray 120 may include a perimeter lip122 extending around the food tray 120. Portions of the perimeter lip122 may include a scallop 126 or cutout formed on opposing ends of thefood tray 120 although the scallop may be formed on all sides of thefood tray 120 or the scallops 126 may be omitted altogether. As shown inFIG. 9, the adjacently disposed food trays 120 collectively form a foodtray air gap 128 due to the scallops 126 along the perimeter lips 122.The scallops 126 on the end-most ones of the food trays 120 adjacent thecart door 20 may facilitate entry of air into the cold tray air inlet 84or the discharge of air by the upper and lower fans 142, 152 into theupper and lower portions 52, 54 of the container interior 42.

Referring to FIG. 11, shown is a perspective illustration of thecontainer interior 42 having the food tray 120 with scalloped perimeterlips 122 and illustrating the air flow through the food tray air gaps128. As can be seen in FIG. 11, air flow between vertical layers of thefood trays 120 is facilitated by the food tray air gap 128. FIG. 11additionally illustrates the discharge of air from the upper fan 142into the upper airflow circuit 106 which is further facilitated by thescallops 126 formed in the perimeter lip 122 of the food trays 120.

Referring to FIG. 12, shown is a sectional illustration of the containersystem 10 illustrating the mounting of the cold tray 80 on one of thetray supports 48. FIG. 12 further illustrates an optional embodimentwherein one or more of the food trays 120 are mounted immediately abovethe cold tray 80 such that the food tray 120 is in direct contact withthe top side 94 of the cold tray 80. As was earlier indicated,substantially direct contact between the food tray 120 and the cold tray80 facilitates conduction of heat therebetween in order to maintain thetemperature of the contents of the food tray 120 at a desired level. Ascan be seen in FIG. 12, the cold tray 80 may include longitudinalrecesses 92 formed along lateral sides of the cold tray 80 for receivingthe tray supports 48. In this regard, the cold tray 80 is preferablysized to have an overall width that is substantially complementary tothe distance between the side walls 16 of the galley cart 12. However,the cold tray 80 may be formed in any suitable width.

FIG. 12 further illustrates one of the food trays 120 mounted below thecold tray 80 and wherein the food tray 120 is supported by the traysupports 48 extending along the side walls 16 of the galley cart 12. Thespacing between the food tray 120 and the cold tray 80 may be sized toaccommodate food items (not shown) on the food tray 120 and to providespace between the food items and the cold tray 80 facilitate the flow ofcooled air over the top of the food tray 120. Although the tray supports48 for the cold tray 80 are illustrated as having a larger size (i.e.,larger cross sectional area) than the tray supports 48 which support thefood trays 120, it is contemplated that substantially all of the traysupports 48 within the galley cart 12 (FIG. 11) may be of substantiallyequivalent size, shape and configuration such that the food trays 120and cold tray 80 may be interchangeably mounted at any vertical locationwith the galley cart 12.

FIG. 13 is a perspective illustration of a portion of a wall of thecontainer body 14. The wall portion illustrated in FIG. 13 is preferablyformed in a configuration providing relatively high insulativecapability and having a relatively high R-value or resistance to heatflow across the wall. In an embodiment, the construction illustrated inFIG. 13 may be implemented in any one of the side walls 16, top wall 30,bottom wall 32, end walls 18 and/or cart door 20. In a non-limitingembodiment, the construction illustrated in FIG. 13 may comprise avacuum insulated panel 34 having a relatively high R-value such asbetween approximately 30 and 50.

As illustrated in FIG. 13, the vacuum insulated panel 34 may comprise apair of face sheets 36 forming a gap therebetween. The gap may be sealedalong the edges of the vacuum insulated panel 34 and may be at leastpartially filled with a core 38 for maintaining a vacuum 40 within thevacuum insulated panel 34. The core 38 material is preferably selectedwith appropriate strength to resist collapsing under the effects ofexternal pressure due to the vacuum 40 within the gap. Advantageously,the absence of air within the vacuum insulated panel 34 minimizesconduction and convection of heat across the thickness of the vacuuminsulated panel 34.

A galley cart 12 as illustrated in FIG. 1 may be constructed of vacuuminsulated panels 34 and may exhibit a relatively high R-value tomaintain the air temperature of the container interior 42 at relativelycool temperatures for extended periods of time. The core 38 material ofthe vacuum insulated panel 34 shown in FIG. 13 may be provided in anysuitable configuration capable of maintaining the structural integrityof the panel with the vacuum 40. In an embodiment, the core 38 materialmay comprise aerogel or any other suitable material including, withoutlimitation, foam and fiberglass insulation. The face sheets 36 may beformed of any suitable metallic or nonmetallic material and maypreferably be generally impermeable to prevent loss of vacuum 40 withinthe vacuum insulated panel 34.

Referring to FIG. 14, shown is a top sectional illustration of thecontainer system 10 illustrating a plurality of food trays 120 in analternative embodiment wherein the food trays 120 include a plurality ofvent holes 124 formed in the perimeter lips 122. The food trays 120 maybe disposed in generally abutting or contacting relation in anend-to-end arrangement relative to one another when mounted on the traysupports 48. As was described above with regard to FIG. 9, the end-mostone of the food trays 120 is preferably mounted to provide a food trayair gap 128 between the end-most one of the food tray 120 and the cartdoor 20 to facilitate the flow of air between the food tray 120 and cartdoor 20. In this manner, air discharged by the air flow source 132(e.g., circulation fan 140) may be circulated through the layers of foodtrays 120 prior to the air being drawn into the cold tray air inlet 84at the back end 88 of the cold tray 80.

FIG. 15 illustrates a perspective view of the embodiment of the foodtray 120 having the vent holes 124 disposed in spaced arrangement aroundthe perimeter lip 122 of the food tray 120. Although shown as beingformed as elongated slots, the vent holes 124 may be formed in any size,shape and configuration and at any location within the food tray 120.The food trays 120 are illustrated as being supported on the traysupports 48 or support rails 50. The food tray 120 may be provided in agenerally symmetrical configuration to allow for mounting of the foodtray 120 on the support rail 50 in any orientation. Non-symmetricalconfigurations of the food trays 120 are also contemplated.

Referring to FIG. 16, shown is a perspective illustration of thecontainer interior 42 illustrating the plurality of the food trays 120having the vent holes 124 installed in the perimeter lips 122. As can beseen in FIG. 16, the vent holes 124 facilitate the flow of air betweenthe food trays 120. The vent holes 124 provide a means for mixing of theair between the layers of food trays 120 within the container interior42. Likewise, the vent holes 124 may be formed along the perimeter lips122 adjacent the side walls 16 of the galley cart 12. The vent holes 124may facilitate further mixing of air between the layers of food trays120 wherein air may flow along the side walls 16 and through the ventholes 124 in the perimeter lips 122.

Referring now to FIGS. 17-19, shown is an embodiment of the cold tray 80having the fan module 134 integrated with the cold tray 80. The fanmodule 134 may include the upper and lower fans 142, 152 mounted in thefront end 86 of the cold tray 80 and having the cold tray air inlet 84disposed on a back end 88 of the cold tray 80. The cold tray housing 82may have a generally hollow interior for housing a refrigerant 188. Aswas earlier indicated, the refrigerant 188 may be contained within oneor more cold packs 180 which may be inserted within the cold trayhousing 82. The cold trays 80 are preferably configured such that airdrawn into the cold tray air inlet 84 from the container interior 42passes between the cold pack 180 and the cold tray housing 82 beforebeing discharged back into the container interior 42 by means of thecirculation fans 140 (i.e., upper and lower fans 142, 152).

In FIG. 17, shown is an embodiment of the cold tray 80 wherein the upperfan 142 may be located within the front end 86 of the cold tray 80. Theupper fan 142 draws air from the cold tray air inlet 84 through the coldtray housing 82 and discharges the air through the upper nozzle 148 intothe container interior 42. The upper nozzle 148 forms the upper fanoutlet 150 which may terminate substantially flush with the fancompartment shell 138. In this regard, the fan compartment 136 maycomprise upper and lower shell halves which may be joined by anysuitable means such as by mechanical attachment and/or adhesive bondingor any other suitable means. The fan compartment 136 may include thebattery status indicator 168 which may optionally be included on thefront end 86 of the cold tray 80 or at any other suitable location. Thefan compartment 136 may house the power source 164 such as the batterypack 166 which may be mounted within or on the fan compartment 136 or onan interior or exterior of the container 11.

Referring to FIG. 18, shown is a bottom side of the cold tray 80 andillustrating a lower fan outlet 160 for discharging air into thecontainer interior 42. As can be seen in FIG. 18, the lower fan outlet160 may be mounted toward a lateral side 90 of the fan compartment 136opposite the upper fan 142. The upper and lower fan outlets 150, 160 maydistribute cooled air into the respective ones of the upper and lowerairflow circuits 106, 108. FIG. 18 further illustrates a portion of thelongitudinal recess 92 which may extend from a front end 86 of the coldtray 80 to a back end 88 of the cold tray 80 and which may be engageableto the tray supports 48 as illustrated in FIG. 12 described above. Inthis regard, the longitudinal recess 92 may be sized complementary to alength of the tray support 48 illustrated in FIG. 12 in order to fix theposition of the cold tray 80 relative to the door inner surface 44 suchthat the cold tray end gap 98 is provided as best seen in FIGS. 9 and14.

Referring to FIG. 19, shown is an end frame 102 of the cold tray housing82. The end frame 102 may be pivotably mounted to the back end 88 of thecold tray 80 and may be movable in a manner that facilitates theinstallation and removal of one or more cold packs 180 into the coldtray housing 82. In this regard, the end frame 102 may include an endframe hinge 104 which may comprise a living hinge arrangement whereinthe material of the hinge comprises a reduced thickness of the materialjoining the end frame 102 to the cold tray housing 82. Alternatively,the end frame hinge 104 may comprise one or more individual mechanicalhinge elements to allow pivoting of the end frame 102 from an operatingposition (illustrated in solid line font in FIG. 19) to a loadingposition (illustrated in dashed line font in FIG. 19).

As can be seen in FIG. 19, the end frame 102 may be formed as asubstantially hollow or ring-shaped member and may be configured as anextension of the ring-shaped cross-section of the cold tray housing 82as illustrated in FIG. 23. In this regard, the end frame 102 as shown inFIG. 19 may have a generally aerodynamic profile or shape to facilitatethe flow of air around the upper and lower edges of the end frame 102and into the cold tray air inlet 84. However, although shown as agenerally ring-shaped element, the end frame 102 may be formed of anyconfiguration that is suitable for facilitating the flow of air into thecold tray housing 82.

For example, the end frame 102 may include a vent or grating arrangement(not shown) to contain the contents of the cold tray housing 82. The endframe 102 may be secured to the cold tray housing 82 in the operatingposition by means of any suitable method including, but not limited to,mechanical features such as mechanical snaps (not shown) which may beintegrally formed with or separately mounted to the end frame 102 andcold tray housing 82. Advantageously, the pivotable nature of the endframe 102 facilitates the convenient installation and/or removal of oneor more of the cold packs 180 (FIG. 24) from the cold tray housing 82.

Referring briefly to FIG. 24, shown is an embodiment of the cold trayhousing 82 having a plurality of cold packs 180 which may be removedfrom the cold tray housing 82 by downward pivoting of the end frame 102and sliding the cold packs 180 outwardly. However, the cold tray housing82 may be configured in a variety of alternative arrangements tofacilitate removal and installation of the cold packs 180. For example,the cold tray housing 82 may be formed as a pair of upper and lowershells (not shown) wherein the upper shell may be removable from thelower shell to facilitate access to the interior of the cold trayhousing 82 such that the cold packs 180 may be removed and/or installed.Alternatively, the cold tray housing 82 may include one or moreremovable panels (not shown) to facilitate access to the cold packs 180.

Referring to FIG. 20, shown is a top perspective illustration of anembodiment wherein the cold tray 80 and fan module 134 are configured asseparate units. In the non-limiting embodiment illustrated in FIG. 20,the fan module 134 may be formed in a configuration that iscomplementary to the configuration of the cold tray 80. However, the fanmodule 134 may be formed in any suitable size, shape and configurationfor mounting inside the container interior 42 in any suitable manner. Asshown in FIG. 3, the fan module 134 may be mounted inside the containerinterior 42 in end-to-end arrangement with the cold tray 80 such thatthe fan module 134 is in fluid communication with the cold tray 80. Thefan module 134 may include at least one circulation fan 140 such asupper and lower fans 142, 152. A battery pack 166 may optionally beincluded with the fan module 134 for powering the upper and lower fans142, 152.

Referring briefly to FIG. 21, shown is a perspective illustration of thecontainer system 10 showing the pack being detachably mounted to thecart door 20 of the container 11. As was indicated above, the batterypack 166 may provide power to the upper and lower fans 142, 152 withinthe fan module 134 by means of electrical contacts (not shown) betweenthe fan module 134 and the container 11. For example, the electricalcontacts may be located at an interface between the battery pack 166 anda recess in the cart door 20 for receiving the battery pack 166. Inaddition, electrical contacts may be located at an interface between thefan module 134 and the cart door 20 such that power is provided to thefan module 134 when the cart door 20 is closed. Alternatively,electrical contacts may be provided between the fan module 134 and oneor more of the tray supports upon which the fan module 134 is mounted orin any one of a variety of alternative arrangements.

Referring to FIG. 22, shown is a top perspective illustration of thecold tray 80 in a partially exploded view and illustrating a fancompartment shell 138 being removed to expose an interior of the fancompartment 136. Furthermore, FIG. 22 illustrates a plurality of coldpacks 180 mounted within the cold tray housing 82 in end-to-endarrangement relative to one another. The fan compartment 136 may containthe logic circuit 172 and power source 164 or battery pack 166 which maybe configured to be removable from the fan compartment 136 by removal ofthe access panel 170. Alternatively, the battery pack 166 may berechargeable to obviate the need for removing the battery pack. In anembodiment, the battery pack 166 may be recharged by inductive chargingin a manner as will be described in greater detail below.

The logic circuit 172 may include appropriate sensors including, but notlimited to, temperature sensors 174 which may be mounted to the coldtray 80. Furthermore, the container interior 42 may include temperaturesensors 174 which may be communicatively coupled to the logic circuit172 by any suitable means including wireless and/or hardwire connection.Also shown in FIG. 22 are the upper and lower fans 142, 152 which mayinclude respective ones of the upper and lower fan ducts 146, 156 which,in turn, may be connected to respective ones of the upper and lowernozzles 148, 158 forming the upper and lower fan outlets 150, 160 of theupper and lower fans 142, 152, respectively.

Referring to FIG. 24, shown is a side sectional illustration of the coldtray 80 taken along line 24-24 of FIG. 22 and illustrating the locationof the fan compartment 136 housing at the front end 86 of the cold tray80 and the installation of the cold packs 180 within the cold trayhousing 82. FIG. 24 illustrates an embodiment wherein the cold packs 180may be removed and/or installed from the cold tray housing 82 bypivoting the end frame 102 at the back end 88 of the cold tray 80 intothe loading position to facilitate removal of the cold packs 180. Thecold packs 180 may be provided in any suitable size, shape andconfiguration. The cold packs 80 are preferably formed complementary tothe cold tray housing 82 such that air drawn into the cold tray airinlet 84 may pass between the cold packs 180 and the inner surfaces ofthe cold tray housing 82 resulting in cooling of the air prior todischarge into the container interior 42.

Referring to FIG. 23, shown is a cross-sectional illustration of thecold tray 80 of FIG. 22 and illustrating an embodiment of one of thecold packs 180 mounted within the cold tray housing 82. As can be seen,the cold tray housing 82 may include a bottom side 96 having one or moreinternal ribs 100 extending upwardly into the cold tray housing 82. Theinternal ribs 100 may be formed as discontinuous members or ascontinuous members extending along a length of the cold tray housing 82from the front end 86 of the cold tray 80 to the back end 88 of the coldtray 80. However, the internal ribs 100 may be formed as discreteelements such as raised bosses 162 or other surface features for spacingthe cold packs 180 away from the interior of the cold tray housing 82.In this manner, a cold pack air channel 192 may be formed between thecold pack upper and lower surfaces 182, 184 and the cold tray housing82.

The cold pack air channels 192 facilitate the passage of air through thecold tray housing 82. As the air passes along the cold pack 180containing the refrigerant 188, the air is cooled prior to beingdischarged into the container interior 42 by the upper and lower fans142, 152 (FIG. 22). Although FIG. 23 illustrates a cross-section havinginternal ribs 100 disposed on a bottom side 96 of the cold tray housing82, it is contemplated that the cold tray housing 82 may includeinternal ribs 100 formed on a top side 94 of the cold tray housing 82 inaddition to or as an alternative to the internal ribs 100 on the bottomside 96.

Referring still to FIG. 23, the cold pack 180 may be configured to houseany suitable type of refrigerant 188 for maintaining the temperature ofthe container interior 42 to a desired value. For example, the cold pack180 may contain refrigerant 188 configured as a phase change material190 of any suitable composition. The phase change material 190 mayfacilitate cooling of the air as the material changes phase to absorbheat from the air passing by or surrounding the cold pack. The cold pack180 may be formed as a fillable container wherein the cold pack 180 mayinclude an indentation 186 (FIG. 22) for locating a filler cap (notshown) that may be removed to allow for emptying of the contents of thecold pack 180 and refilling the cold pack 180 with the same refrigerant188 or a different type of refrigerant. Alternatively, the cold pack 180may be formed in a substantially non-fillable arrangement wherein thecold pack 180 is used for a predetermined number of cycles after whichthe cold pack 180 may be discarded or recycled.

Referring to FIG. 23, the phase change material 190 may be formed as anysuitable composition including, but not limited to, a carboxymethylcellulose-based composition. Alternatively, the phase change material190 may be formed as a polymer gel formulation which may be contained orhoused within a cold pack 180 having a flexible or rigid construction.For example, the cold pack 180 may comprise a generally flexiblepolymeric film formed as a pouch containing the phase change material.Alternatively, the cold pack 180 may comprise a relatively inflexiblepolymeric shell construction such as, without limitation, polyethyleneor nylon or any other suitable material that may be injection molded orblow molded or otherwise fabricated.

Advantageously, the composition of the phase change material 190 ispreferably selected to provide a relatively high rate of absorption ofheat contained in the air flowing past the cold pack. The phase changematerial 190 may change in phase from a solid to a gas such as may occurduring the sublimation of dry ice. The phase change material 190 mayalso change phase from solid to liquid or from liquid to gas. The phasechange material 190 may comprise frozen water (i.e., ice) or morecomplex compositions. For example, the refrigerant 188 may include aphase change material 190 comprising a co-polymer based material (e.g.,polyacrylate polyalcohol co-polymer). In this regard, the phase changematerial 190 may comprise any organic or inorganic composition orcombination thereof without limitation such as a paraffin-basedcomposition or a salt hydrate-based composition. The phase changematerial 190 preferably has a relatively high latent heat per unitvolume to provide cooling capability for extended durations.

Referring to FIG. 37, shown is a chart illustrating the latent heat forphase change material comprising dry ice and water ice. The dry ice isindicated in FIG. 37 by element numeral 324 and exhibits a latent heatof approximately 246 Btu/lb as compared to water ice indicated byelement numeral 326 which exhibits a latent heat of approximately 144Btu/lb. The phase change material may be provided in any suitable formsuch as, without limitation, any commercially available phase changematerial. For example, the phase change material may be provided as arefrigerant brick (not shown) having a suitable latent heat. The foambrick may be formed from rigid open-celled foam and may be impregnatedwith any suitable solution such as an aqueous solution or any othersolution. The foam may be sealed within a pouch such as a polyethylenepouch or a pouch formed of any other suitable material for containingthe foam. As was earlier indicated, the phase change material mayoptionally comprise a carboxymethyl cellulose-based composition whichmay also be contained within a pouch or container such as a nylon orpolyethylene pouch or within a relatively inflexible or rigid container.The phase change material may also comprise any suitable vegetable-basedmaterial.

Referring to FIG. 38, shown is a chart illustrating the relativeperformance of the container system 10 (FIG. 1) as a function of phasechange material and the R-value of the container body 14. Morespecifically, FIG. 38 is a plot of mass (e.g., pounds) of refrigerantvs. elapsed time during which the mass of phase change materialmaintains the container interior 42 below a predetermined temperature.In this regard, FIG. 38 illustrates the performance of a carboxymethylcellulose-based phase change material in different quantities measuredin pounds and the time period during which the container interior 42 ismaintained below a temperature of 4° C. for a cart having two differentR-values. For example, FIG. 38 illustrates a plot of the performance ofa galley cart 12 having a collective R-value of 15 as compared to agalley cart 12 having a collective R-value of 20. The collective R-valueof the galley cart 12 may be defined as the collective insulativecapability of the side, top and bottom walls 16, 30, 32 and the cartdoors 20 that enclose the container interior 42 as shown in FIG. 2.

Shown also in FIG. 38 are empirical data points which closely correspondto the analytical data for the two plots. The empirical data points areprovided to validate the analytical performance of the phase changematerial in the different quantities relative to the elapsed time duringwhich the container interior 42 is maintained below 4° C. As can be seenin the graph of FIG. 38, the cart configuration having an R-value of 15exhibits a shortened elapsed time for maintaining the container interior42 below 4° C. as compared to the cart configuration having a collectiveR-value of 20. For example, FIG. 38 illustrates that for a quantity of 2pounds of phase change material in a cart configuration having acollective R-value of 15, the air temperature of the container interior42 is maintained below 4° C. for approximately 3.5 hours as compared tothe same quantity of phase change material in a cart configurationhaving a collective R-value of 20 and which provides an elapsed time ofalmost 5 hours during which the air temperature within the containerinterior 42 is maintained below 4° C. As can be seen, the R-value of thegalley cart 12 (FIG. 1) may be a significant factor in the refrigerationcapability of the container system 10 (FIG. 1).

Referring to FIG. 39, shown is a comparison of different refrigerants asused in cart configurations having substantially similar R-values. Forexample, FIG. 39 represents a plot of air temperature versus elapsedtime for a carboxymethyl cellulose-based phase change material ascompared to a foam brick refrigerant. As can be in FIG. 39, the plotindicated by reference numeral 364 represents the air temperature of thecontainer interior 42 (FIG. 2) for a cold tray 80 containing 5.5 poundsof foam brick refrigerant. Reference numeral 366 indicates a plotrepresenting the air temperature of the container interior 42 for a coldtray 80 containing 7.1 pounds of carboxymethyl cellulose-basedcomposition phase change material in a cart having a collective R-valueof 20. As can be seen by comparing the two plots for the differentquantities and types of phase change material, the larger quantity ofcarboxymethyl cellulose-based composition provides improved coolingcapability as compared to the configuration containing a relativelysmaller quantity (e.g., 5.5 pounds) of the foam brick refrigerant.

Referring again to FIG. 23, shown is the cold tray 80 which may containany one of a variety of different types of refrigerants withoutlimitation and which may include one or more of the phase changematerials such as those illustrated in FIG. 37 and described above. Theselection of the phase change material 190 may be based in part upon thedesired temperature at which the container interior 42 (FIG. 2) may bemaintained and the amount of time for maintaining such temperature. Forexample, a phase change material 190 having a relatively high latentheat may be desired for maintaining the container interior 42 at arelatively low temperature for relatively short durations.

Alternatively, a refrigerant 188 having a relatively low latent heat maybe desired in larger quantities for maintaining the air temperature ofthe container interior 42 at a desired temperature for extendeddurations. In an embodiment, the phase change material 190 may comprisea eutectic material comprising a composition of two or more substanceshaving a melting point that is lower than the melting point of each oneof the individual substances. For example, the phase change material 190may comprise a carboxymethyl cellulose-based composition having a phasetransition temperature of approximately −20° C. which may be thetemperature at which the material changes from a solid to a liquid. Therefrigerant 188 may be selected based upon any one of a variety ofdifferent factors and is not limited to the air temperature at which thecontainer interior 42 is to be maintained or the duration over which thetemperature may be maintained.

Referring now to FIG. 25, shown is a top view of the fan compartment 136of the cold tray 80 illustrating the relative positions of the upper andlower fans 142, 152 in an embodiment. As was earlier indicated, the coldtray 80 may comprise one or more circulation fans 140. In this regard,the arrangement illustrated in FIG. 25 is an example of any one of avariety of different arrangements for mounting the circulation fans 140to or within the cold tray 80. Further in this regard, FIG. 25 is anon-limiting example of the positioning of the circulation fans 140 atone of the opposing ends of the cold tray 80 and is not to be construedas limiting alternative arrangements which may include positioning oneor more circulation fans 140 at alternative locations along the lengthof the cold tray 80.

FIG. 25 further illustrates the logic circuit 172 for controlling thecirculation fans 140 such as the upper and lower fans 142, 152. Thelogic circuit 172 may be communicatively coupled to one or moretemperature sensors 174 which may be mounted to the cold tray 80 andwhich may be mounted within the container interior 42 and wirelesslyand/or hardwired to the logic circuit 172. One or more thermostats 176may also be included with the logic circuit 172 for regulating theoperation of the upper and/or lower fans 142, 152. As can be seen inFIG. 21, air that is drawn through the cold tray housing 82 may enterthe upper fan inlet 144 illustrated in FIG. 25.

The air is then passed through an upper fan duct 146 before exiting theupper fan outlet 150. Similarly, air drawn through the cold tray housing82 by the lower fan 152 enters the lower fan inlet 154 and passesthrough the lower fan duct 156 and is then is discharged into thecontainer interior 42 through the lower nozzle 158 and lower fan outlet160. It should also be noted that the arrangement of the circulation fan140 may comprise a singular fan having a single impeller and from whichtwo or more ducts (not shown) may extend such as from opposing sides ofthe fan housing. As may be appreciated, the cold tray 80 may compriseany suitable arrangement of circulation fans 140 for drawing air intothe cold tray 80 and discharging the air back into the containerinterior 42.

Referring to FIG. 26, shown is a cross-sectional illustration of the fancompartment 136 illustrating the mounting of the upper and lower fans142, 152 to the fan compartment 136 such as by means of one or morebosses 162. The bosses 162 may facilitate mechanical attachment ofrespective ones of the upper and lower fans 142, 152 to the fancompartment shell 138 although the upper and lower fans 142, 152 may bemounted to the cold tray 80 by any suitable means. As can be seen inFIG. 26, air flows through the upper and lower fans 142, 152 and isdischarged out of the cold tray 80 from respective upper and lower fanoutlets 150, 160 to form the upper and lower airflow circuits 106, 108within the container interior 42 as best seen in FIG. 6.

Referring to FIG. 27, shown is a perspective illustration of analternative embodiment of a cold pack 180 mounted within the cold trayhousing 82. As shown in FIG. 27, the cold pack 180 may comprise one ormore cold packs 180 that may collectively define a generally streamlinedshape in order to facilitate the flow of air between the cold trayhousing 82 and the cold pack. FIG. 28 is a sectional illustration of thealternative embodiment of the cold pack 180 illustrated in FIG. 27. Ascan be seen in FIG. 28, the embodiment of the cold pack 180 mayoptionally include recesses extending along a length of the cold pack180 to define upper and/or lower cold pack air channels 192 that improveair flow through the cold tray housing 82. The cold tray housing 82 mayinclude internal ribs 100 which may be optionally formed on the top side94 and/or bottom side 96 of the cold tray housing 82 to space the coldpack 180 away from the cold tray housing 82 and facilitate air flowtherebetween.

FIG. 29 is a top view of the cold tray 80 illustrating a profile of thecold pack 180 in the streamlined embodiment. As can be seen in FIG. 29,the cold pack 180 may be provided as two individual cold pack 180elements. In an embodiment, the cold packs may be mirror-images of oneanother and mounted in back-to-back arrangement. Alternatively, the coldpack 180 may include an intermediate cold pack configured to be mountedbetween the end-most ones of the cold packs 180 to preserve the crosssectional shape for airflow efficiency. Each one of the cold packs 180may optionally include an indentation 186 to accommodate a filler cap tofacilitate emptying the contents of the cold pack 180 and refilling thecold pack.

FIG. 30 is a side sectional illustration taken along line 30-30 of FIG.29 and illustrating a streamlined profile shape of the cold pack 180 forfacilitating the flow of air through the cold tray housing 82 from theback end 88 toward the front end 86 of the cold tray housing 82. Alsoillustrated in FIG. 30 is a cold tray end gap 98 which is preferablyprovided between the cart door 20 and the cold tray air inlet 84 tofacilitate drawing of air into the cold tray housing 82. Likewise, thefront end 86 of the cold tray 80 may be mounted in spaced relation tothe cart door 20 to facilitate mixing of air discharged by the upper andlower fans 142, 152. It should also be noted that although FIGS. 24 and30 illustrate configurations of the cold tray 80 that may containrefrigerant, the present disclosure contemplates the installation ofspacer packs 194 within the cold tray housing 82. The spacer packs 194may be substantially devoid of refrigerant 188 and may be included withcold packs 180 containing refrigerant. A set of cold packs 180containing one or more spacer packs 194 may be installed inside a singleone of the cold trays 80 as a means to preserve the flow of air over andaround the cold pack 180 assembly within the cold tray housing 82.

For example, FIG. 24 may include a spacer pack 194 as a substitute forany one of the three cold packs 180 mounted in the cold tray 80.Likewise, the back-to-back arrangement of the streamlined-shaped coldpacks 180 illustrated in FIG. 30 may include a spacer pack 194. A spacerpack 194 may be desired wherein only a portion of the container interior42 may comprise food trays 120. For example, a majority of the foodtrays 120 may be located adjacent to a front end 86 of the cold tray 80such that a cold pack 180 is required in the front end 86 of the coldtray housing 82. The back end 88 of the container interior 42 may bedevoid of food trays 120 obviating the need for a cold pack 180 towardthe back end 88 of the cold tray 80. As may be appreciated, the desirefor including a spacer pack 194 in the cold tray 80 may be based upon avariety of alternative factors.

FIG. 31 is a side sectional illustration of an aircraft 200 cabininterior illustrating a galley area 208 of the cabin and illustrating aplurality of seats 202 arranged in seat rows 204 separated by seataisles 204. The seat rows 204 are located forward and aft of the galleyin the conventional manner. FIG. 31 illustrates a galley cart 12 priorto installation in a cart storage slot 212 of the galley structure 214.The cart storage slot 212 may be mounted below a countertop 210 of thegalley area 208. In this regard, the galley area 208 may include aplurality of cart storage slots 212 configured to receive one or more ofthe galley carts 12.

FIG. 32 is a top view of the aircraft 200 galley area 208 taken alongline 28-28 of FIG. 27 and illustrating an arrangement of the galley area208 comprising multiple cart storage slots 212. As was indicated above,the self-contained nature of the cold tray 80 minimizes or eliminatesthe need for active refrigeration such as chiller units in the galleyarea 208. In addition, the absence of aircraft refrigeration mayeliminate the need for the ducting and gaskets necessary for coolingconventional galley carts. Without the space required for ducting andgaskets of the prior art, the footprint of the galley area 208 maygenerally be reduced in certain aircraft cabin configurations such thatan additional row of seats 202 may be added to the aircraft cabin.

FIG. 33 is a perspective illustration of the galley cart 12 installedinside a galley structure 214 in the galley area 208 (FIG. 31-32). Thegalley structure 214 may form a cart storage slot 212 for housing agalley cart 12 during periods of non-use. In an embodiment, thecontainer system 10 may comprise an inductive charging system 218 forcharging the battery pack 166 during such periods of non-use of thegalley cart 12. As was earlier indicated, the battery pack 166 may bemounted to or contained within the cold tray housing 82, the fan module134 or the container body 14 for powering the one or more circulationfans 140 of the cold tray 80 (FIG. 34).

The container system 10 may optionally be provided with the capacity forcharging the battery pack 166 by an inductive charging unit 220. In thisregard, the battery pack 166 may be inductively coupled to the inductivecharging unit 220 which may be integrated with or mounted to the galleystructure 214. For example, FIG. 33 illustrates the galley structure 214including a structure back wall 216. The structure back wall 216 mayinclude a transmitter 222 for inductively coupling to a receiver 224which may be mounted to the cold tray 80 (FIG. 34). The receiver 224 onthe cold tray 80 may be communicatively coupled to the battery pack 166for recharging the battery pack 166 when the galley cart 12 is dockedwithin the galley structure 214 and the inductive charging system 218 isactivated.

In this regard, the inductive charging unit 220 may be activated suchthat an electromagnetic field 228 is generated by the transmitter 222and is inductively coupled to the receiver 224 across the relativelyshort distance between the transmitter 222 and the receiver 224. Thereceiver 224 on the cold tray 80 may convert the electromagnetic field228 into electrical current for charging the battery pack. As can beseen in FIG. 33, the electromagnetic field 228 may extend across an airgap 226 between the cart door 20 and the structure back wall. The galleystructure 214 may be configured to maintain the air gap 226 at arelatively short distance such as approximately 1 inch although the airgap 226 may comprise any distance. The electromagnetic field 228 mayextend across the air gap 226 between the galley structure 214 and thegalley cart 12, across the thickness of the cart door 20 and across thecold tray end gap 98 between the cold tray 80 and the cart door 20.

Referring to FIG. 34, the inductive charging system 218 may beconfigured to charge the battery pack 166 (FIGS. 21-22). For example,the upper and lower fans 142, 152 (FIG. 22) described above may requirea relatively low-voltage power supply such as a 12-volt system anddrawing relatively small amounts of electrical current such as less thanapproximately 0.5 amps. However, the power source 164 and upper andlower fans 152, 152 may be provided in any suitable voltage range andcurrent draw. The electromagnetic field 228 may be may be transmittedthrough the materials that make up the container system 10. Suchmaterial may be substantially electromagnetically transparent at leastin the location of the inductive charging system 218. For example, atleast a portion of the cart door 20 may be formed of fiberglass, pressedfiberboard, polymeric material and any other substantiallyelectromagnetically transparent materials. The galley structure 214 maybe sized and configured to accommodate the transmitter 222 such that thetransmitter 222 may be integrated into the galley structure 214 ormounted to the galley structure 214.

Referring to FIGS. 35-36, shown is an embodiment of the container system10 wherein the air circulation fan 140 may be powered by an air supply230 as an alternative to electric-motor driven embodiments of thecirculation fan 140 powered by an electrical power source such as thebattery pack 166 described above. Shown in FIG. 35 is a top sectionalview of the container system 10 docked within the galley structure 214.The air circulation fan 140 is shown mounted within the fan module 134or cold tray 80 and is fluidly coupled to the air supply 230 when thegalley cart 12 is docked in the galley structure 214. The air supply 230may comprise a conduit containing compressed air of an existing aircraftsystem. For example, the compressed air supply 230 may be drawn from theaircraft gasper air system (not shown) which may originate as enginebleed air that may be conditioned and routed to the galley and/or alongthe overhead sections (not shown) above the passenger seats. However,the air supply 230 may be provided by any suitable source and is notlimited to drawing air from the gasper air system.

Referring still to FIG. 35-36, the air supply 230 may terminate at afitting 234 such as a quick-disconnect fitting optionally mounted to thecontainer 11 for engaging the air supply 230. The fitting 234 and theair supply 230 may optionally include a one-way valve (not shown) toseal the air supply 230 and the cold tray 80 or fan module 134 duringperiods of non-use. The air supply 230 may provide a flow of air such ascompressed air to a turbine 232 that may be mechanically coupled to thecirculation fan 140 mounted within the fan module 134, cold tray 80 ormounted to the container 11. The turbine 232 may include vanes (notshown) that may be rotatably driven by the air supply 230 causing thecirculation fan 140 (e.g., upper fan) to discharge air from the coldtray 80 to the container interior 42.

The galley cart 12 may be configured such that the air supply 230illustrated in FIGS. 35-36 is engaged to the galley cart 12 at thefitting 234 when the galley cart 12 is inserted into the galleystructure 214 as illustrated in FIGS. 31-32. Alternatively, the airsupply 230 may be connected to the air turbine 232 by means of ductingand/or gaskets (not shown). Advantageously, the air-driven arrangementof the circulation fan 140 illustrated in FIGS. 35-36 may reduce theweight, complexity and maintenance associated with an electric-motordriven circulation fan.

Referring now to FIG. 40, shown is a flow chart illustrating operationsfor implementing the container system 10 (FIG. 1) as disclosed herein.In this regard, FIG. 40 illustrates various operations that may beincluded in implementing one or more container systems for use in anyone of a variety of industries including, without limitation, use inairline operations. For example, in step 400, galley carts 12 (FIG. 1)may be taken from storage and the interiors may be filled with foodtrays 120 comprising food entries, trays, utensils and/or beverages. Asindicated above, a caterer may prepare the food items to create airlinemeals for distribution to passengers during the course of a flight on acommercial airliner. In step 402, the food trays 120 containing preparedfood items may be loaded within the container interior 42 by mountingthe food trays 120 on the tray supports 48 in a manner as illustrated inFIGS. 3-6.

FIG. 40 further illustrates step 402 which may include storing theloaded galley carts 12 (FIG. 1) within a walk-in refrigerator (notshown) for maintaining the temperature of the galley carts 12 at a safelevel. The refrigerator may have a relatively low ambient airtemperature of approximately 3° C. sufficient for maintaining thecontainer interior 42 at a temperature of 4° C. or any other suitablylow temperature. The individual carts may be stored within the walk-inrefrigerator for a desired time period which may extend to 6 hours orbeyond in anticipation of an upcoming airline flight.

In step 404, shortly before departure of the aircraft, the galley carts12 (FIG. 1) may be loaded with cold trays 80 wherein the cold trays 80may be filled with cold packs 180 containing a selected refrigerant. Thecold trays 80 may be installed at the desired location in the containerinterior 42 such as by mounting the cold trays 80 on the tray supports48 similar to that which is illustrated in FIGS. 2 and 8. Fan modules134 may be provided separately from the cold trays as removable units orintegrated with the galley carts as described above. The cart doors 20of the galley cart 12 may be latched closed and the galley carts 12(FIG. 1) may be transported to the aircraft just prior to departure. Thecarts may be loaded onto a truck and may be transported to the aircraft.

In step 406, the galley carts 12 (FIG. 1) may then be loaded onto theaircraft 200 and may be stored in the galley area 208 as illustrated inFIGS. 27-28 and as described above. For example, each one of the galleycarts 12 may be received within a cart storage slot 212 of the galleyarea 208. The battery packs may optionally be inductively charged usingthe inductive charging unit 220 if included within the galley structure214. At any time during the process of loading the galley carts 12 ontothe aircraft 200 or at any other time when food and/or other items arestored within the container interior 42 (FIG. 2), the cold trays 80 maybe activated. In this regard, the upper and/or lower fans 142, 152 (FIG.18) may be activated in order to maintain the temperature of thecontainer interior 42 below a desired level.

Electrical power may be provided to the circulation fans 140 by means ofthe battery pack 166 or by any other suitable electric power sourceincluding an aircraft power system. Alternatively, the circulation fans140 may be powered by the air supply 230 as illustrated in FIGS. 35-36and as described above. The amount of time starting from loading of thegalley carts 12 onto the aircraft 200 until aircraft departure maycomprise approximately 1.5 hours although the amount of time may varydepending upon a variety of factors.

Referring still to FIG. 40, step 408 of the method may include removingindividual galley carts 12 from the carts storage slots 212 (FIG. 28)and initiating the meal service process of distributing the airlinemeals to passengers. During meal service, the cart doors 20 may be openand closed for removal of food trays 120. The cold tray 80 and galleycart 12 (FIG. 2) may preferably be configured to maintain the airtemperature of the container interior 42 to less than approximately 7°C. in the aircraft cabin environment which may have an ambienttemperature of higher than approximately 22° C. by operating the upperand lower fans 142, 152 as needed or on a preprogrammed basis.Alternatively, the cold tray 80 and galley cart 12 (FIG. 2) may beconfigured to maintain the air temperature of the container interior 42to less than approximately 4° C. in a cabin environment having anambient temperature of higher than approximately 22° C. As indicated inFIG. 40, the occurrence of the first meal service in step 308 may occurat an elapsed time of 7.5 hours or longer after initial loading of thegalley carts 12 onto the aircraft.

FIG. 40 further illustrates step 410 comprising a second meal servicewherein the cart doors 20 may again be opened and closed as need duringdistribution of the food trays 120 to the passengers. As indicatedabove, the container system may be configured to maintain the airtemperature within the container interior 42 to below a desired minimum,(e.g. 7° C.) for an elapsed time of approximately 15 hours or longeralthough the total elapsed time within which the temperature may bemaintained is dependent upon the type of refrigerant 188 containedwithin the cold tray 80 and the collective R-value (i.e., thermalresistance) of the galley cart 12. Following the second or final mealservice, the galley carts 12 may be returned to the cart storage slots212 in the galley area 208 (FIG. 27-28) wherein the battery packs 166(FIG. 18) may be inductively charged by inductive coupling to the galleystructure 214 similar to that which is illustrated in FIGS. 29 and 30and described above. Alternatively, the battery packs 166 may bereplaced and new battery packs 166 may be installed within the coldtrays 80 as needed. In a further embodiment, the circulation fans 140may be powered by the air supply 230 when the galley carts 12 are dockedat the galley structure 214 and are coupled to the air supply 230 asillustrated in FIGS. 35-36.

In step 412 following landing of the aircraft, the galley carts 12(FIG. 1) may be removed from the aircraft and transported to a cateringfacility wherein the carts may be unloaded in step 414. The cold trays80 and food trays 120 (FIG. 2) may be removed and the galley cart 12 andfood trays 120 may be cleaned. Step 416 may comprise sorting the galleycarts 12 and organizing and parking the carts in preparation for thenext flight. The cycle may be repeated starting with step 400 whereinthe galley carts 12 may be removed from storage and the food trays 120may be filled with food entries, utensils and again loaded into thecontainer interior 42 using the tray supports 48. The cold trays 80(FIG. 2) may also be loaded into the galley carts 12 prior totransporting the galley carts 12 to the aircraft. However, the coldtrays 80 may be loaded and removed from the galley cart 12 at any time.

Referring now to FIG. 41, shown is a flow chart illustrating a methodfor refrigerating the galley carts 12 (FIG. 1) for maintaining the airtemperature of the container interior 42. The method may comprise step500 of mounting one or more cold trays 80 in the cart at the desiredlocation. For example, the cold tray 80 (FIG. 5) may be mounted at anapproximate mid-height 110 of the container interior 42 as illustratedin FIG. 5 such that the cold tray 80 divides the container interior 42into upper and lower portions 52, 54. As was earlier indicated, the coldtray 80 may comprise a cold tray housing 82 which may include one ormore cold packs 180 (FIG. 12). The cold packs 180 may contain arefrigerant 188 such as a phase change material 190 for cooling airwhich passes by or surrounds the refrigerant. The refrigerant 188 may becontained within the cold pack 180 which may be removably housed withinthe cold tray 80. The cold tray 80 may be fluidly coupled to an air flowsource 132. The air flow source 132 may include at least one circulationfan 140 (FIG. 22) and, in a preferable embodiment, may include an upperfan 142 and a lower fan 152 which may be mounted to a front end 86 ofthe cold tray 80 within a fan compartment 136 housing as best seen inFIG. 22. The circulation fan 140 may be mounted to the cold tray 80and/or the container 11 as described above.

Referring still to FIG. 41, step 502 may comprise positioning the coldtray 80 at the desired location within the container interior 42. Thefan module 134, if provided as a separate, removable unit, may also bemounted within the container interior 42. Step 504 may comprise drawingair from the container interior 42 through the cold tray air inlet 84and into the cold tray housing 82 using the circulation fans 140 (i.e.,upper and lower fans 142, 152) such that the air passes over orsurrounds the refrigerant 188 which may be housed within one or morecold packs 180. FIG. 6 illustrates the discharge of air from the coldtray 80 by upper and lower fans 142, 152 which respectively generate theupper and lower airflow circuits 106, 108 which may move in acounter-rotating pattern relative to one another.

Step 506 comprises powering a circulation fan 140 such as the upper andlower fans 142, 152 using a power source 164 such as a battery pack 166.However, the upper and lower fans 142, 152 may be powered by anysuitable power source 164 and are not limited to a battery pack 166. Aswas described above, the battery pack 166 may be located within the fancompartment 136 as best seen in FIG. 22 or to an exterior of thecontainer 11 such as to the cart door 20 as illustrated in FIG. 21. Thefan compartment 136 may include an access panel 170 for allowing accessto the battery pack 166 for replacing the battery pack 166 and/or forallowing access to the logic circuit 172 which may regulate operation ofthe upper and lower fans 142, 152.

Step 508 of the method illustrated in FIG. 41 may comprise operating theupper and lower fans 142, 152 to direct the air into the upper and lowerportions 52, 54 of the container interior 42 to form the upper and lowerairflow circuits 106, 108. Advantageously, the orientation andpositioning of the upper and lower fans 142, 152 on the front end 86 ofthe cold tray 80 facilitates establishment of the upper and lowerairflow circuits 106, 108 wherein air flow from the front end 86 towardthe back end 88 of the container interior 42. The air may pass over thelayers of food trays 120 and is then drawn back into the cold trayhousing 82 at the cold tray air inlet 84. The power may be provided tothe upper and lower fans 142, 152 in a manner to maintain the airtemperature within the container interior 42 below a predeterminedlevel. In this regard, temperature sensors 174 may be mounted atlocations within the container interior 42 to provide signalsrepresentative of the temperature at various locations within thecontainer interior 42. Alternatively, one or more temperature sensors174 may be incorporated into or mounted with the cold tray 80 such as onan exterior of the cold tray 80 adjacent the upper and lower fans 142,152 in order to sense the temperature of the air within the containerinterior 42.

Step 510 may comprise maintaining the temperature within the containerinterior 42 below approximately 7° C. In this regard, the temperature ofthe container interior 42 may be maintained at any predetermined value.An embodiment of the container system 10 (FIG. 1) may compriseconfiguring the cold tray 80 and galley cart such that the airtemperature of the container interior 42 is preferably maintained at atemperature of less than approximately 7° C. and, more preferably, at atemperature of less than approximately 4° C. for a duration of at leastapproximately 15 hours or longer when the cart is in environment havingan ambient temperature of higher than approximately 22° C. or higher. Inthis regard, the 15-hour duration represents the portion of a long-haulcommercial airline flight wherein the container system 10 may beoperated in a substantially self-contained manner to maintain the airtemperature within the container interior 42 starting from the initialloading of the galley carts 12 (FIG. 1) onto the aircraft untilconclusion of the last airline meal service on a flight. The 22° C.(i.e., approximately 72° F.) temperature value represents an approximatecabin temperature within which the container system may maintain the airtemperature of the container interior 42.

Toward this end, step 512 may comprise regulating the operation of theupper and lower fans 142, 152 (FIG. 22) such that heat gain in thecontainer interior 42 is limited to less than approximately 100 Btu/hr.For example an embodiment of the method may comprises limiting the heatgain to less than approximately 65 Btu/hr in an environment having anexternal ambient temperature of at least approximately 29° C. Asindicated above, heat gain of the galley cart 12 may be dependent inpart upon the collective R-value of the container body 14 (FIG. 2) whichmay, in turn, depend upon the insulting efficiency of the door seals 26(FIG. 2) and/or the R-value of the individual panels which make up theside walls 16, top and bottom walls 30, 32 and cart doors 20 of thecontainer body 14.

A higher insulating capacity of the container body 14 may correspond toa reduced duration and frequency of operating the upper and lower fans142, 152. Step 514 of the method of refrigerating the container interior42 may comprise inductively charging the battery pack 166 by providingthe cold tray 80 with a receiver 224 (FIGS. 32-33) for inductivecoupling to a transmitter 222 that may be mounted to a galley structure214 (FIGS. 32-33) or to any other suitable structure. The battery pack166 may be charged in step 516 by inductively coupling the receiver 224of the cold tray 80 to the transmitter 222 which may be mounted at astrategic location within the aircraft cabin such as within the galleyarea 208.

Referring now to FIGS. 42-73, shown are further embodiments of acontainer system 600 including a highly-insulated container 604 (e.g.,FIGS. 42, 53, 61, 68) and one or more refrigerant trays 700 (e.g., FIGS.44, 52, 60) configured to be mounted within the container interior 606.The refrigerant tray 700 may contain a refrigerant 188 that maysublimate from a solid directly to a cold gas 740 when the temperatureof the refrigerant 188 exceeds a sublimation temperature of therefrigerant 188. For example, in a non-limiting embodiment, as mentionedabove, the refrigerant 188 may comprise dry ice 752 (i.e., solid carbondioxide) that may sublimate into gaseous carbon dioxide 754 (FIG. 45)when the temperature of the dry ice 752 exceeds −78° C. (approximately−109° F. at one atmosphere).

Although the refrigerant is described below as comprising dry ice forthe container system embodiments illustrated in FIGS. 42-73, therefrigerant may comprise any material composition, without limitation,that sublimates from a solid to a cold gas when the temperature of therefrigerant exceeds a sublimation temperature. In an embodiment, therefrigerant tray 700 (FIG. 43) may be mounted above one or more foodtrays 120 (FIG. 43) that may be stored within the container 604. Anembodiment of the refrigerant tray 700 (FIG. 44, 52) may includesublimation ports 728 (FIG. 44, 52) to allow the cold gas 740 such ascarbon dioxide gas 754 from dry ice refrigerant to exit the refrigeranttray 700 and circulate through the container interior 606.

As shown in FIGS. 53-54, due to the cold temperature of the cold gas 740or carbon dioxide gas 754 relative to the air within the container 604and due to the high density of cold gas 740 or carbon dioxide gas 754relative to the air density, the cold gas 740 or carbon dioxide gas 754may flow downwardly from the sublimation ports 728 and mix with the airin the container interior 606 to cool the container interior 606.Alternatively, as shown in FIGS. 59-60, the refrigerant tray 700 (FIG.60) may be provided without any openings such that the cold gas 740 orcarbon dioxide gas 754 (FIG. 45) may be generally trapped or containedwithin the refrigerant tray 700. For the refrigerant trays 700 (FIG. 60)lacking openings, the container interior 606 may be cooled by contact ofthe air with the refrigerant tray walls 704, 706, 708, 710 after whichthe cold air 760 (FIG. 59) may sink and displace relatively warm air 762(FIG. 59) causing the warm air 762 to rise and cool when contacting therefrigerant trays 700 and forming one or more convective cycles (FIG.59) as described in greater detail below.

Advantageously, the combination of the refrigerant trays 700 (FIGS. 44,54, 60) and the highly-insulated container 604 (e.g., FIGS. 42, 53, 56,68) provides a passively-cooled system for maintaining food items at asafe temperature for extended periods of time. For example, one or moreof the embodiments of the container 604 and the refrigerant tray 700 maymaintain the air temperature within the container interior 606 at lessthan approximately 7° C. (approximately 45° F.) for extended durations.In an embodiment, the refrigerant tray 700 and the container 604 may beimplemented in a galley cart 602 of an aircraft and may cooperativelymaintain the air temperature within the container interior 606 of thegalley cart 602 at less than approximately 4° C. (approximately 39° F.)for a period of at least approximately 15 hours in an environment (e.g.,an aircraft cabin) having an ambient air temperature of greater thanapproximately 29° C. (approximately 84° F.).

Furthermore, embodiments of the container system 600 (e.g., FIGS. 42,53, 56, 59, 61, 68) may advantageously eliminate a dependency on adedicated mechanical refrigeration system (not shown) for cooling galleycarts 602. Elimination of a dedicated refrigeration system for thegalley carts 602 may also eliminate the noise, cost, and complexityassociated with such mechanical refrigeration systems. In addition,embodiments of the refrigerant tray 700 (e.g., FIGS. 44, 54, 60) may beprovided with a relatively thin profile or relatively low height suchthat the refrigerant tray 700 occupies a relatively small volume of thecontainer interior 606 (FIG. 42). In this manner, the container 604(FIG. 42) may provide storage space for a large quantity of food trays120 (FIG. 42). Furthermore, the relatively low profile refrigerant tray700 may be implemented in existing galley cart configurations such thatairlines may use their existing inventory of galley cart storage bins(not shown) and food trays 120.

Referring to FIGS. 42-43, shown is the container 604 and a refrigeranttray 700 which may be positioned within the container interior 606. Thecontainer 604 may include an opposing pair of side walls 612interconnected by a top wall 614 and a bottom wall 616. The container604 may include a set of casters 680 to facilitate moving the container604. In an embodiment, the container 604 may comprise a galley cart 602containing food trays 120 for serving meals to passengers in an aircraftcabin (not shown). The casters 680 may facilitate moving the galley cart602 up and down main aisles (not shown) of the aircraft cabin. Each oneof the side walls 612, top wall 614 and bottom wall 616 may include oneor more vacuum insulated panels 648. The vacuum insulated panel(s) 648may be sandwiched or captured between an inner shell 650 and an outershell 652 as described in greater detail below.

The container 604 may include a plurality of vertically spaced traysupports 676 or tray rails 678 extending laterally outwardly from aninterior surface 608 of the container interior 606. Although shown asgenerally elongated elements, the tray supports 676 may optionally beconfigured as discrete protrusions or bosses (FIG. 56) located at spacedintervals along the interior surface 608 for supporting the food trays120 and/or the refrigerant tray 700. Even further, the tray supports 676may be configured as apertures or receptacles (not shown) for receivingmating protrusions (not shown) that may be mounted to the food trays 120and/or refrigerant trays 700. Although shown in FIG. 43 as being mountedabove the food trays 120 at an uppermost position within the containerinterior 606, the refrigerant tray 700 is configured to be selectivelymountable to any one of the tray supports 676 or tray rails 678 at anyvertical position within the container interior 606.

Referring to FIGS. 42-43, the container 604 may include a cart door 620on one end of the container 604 or on both ends of the container 604.For configurations including a single cart door 620, the container 604may include a fixed end wall 618 on an end of the cart opposite the cartdoor 620. The cart door 620 may be pivotally mounted to the container604 by means of hinges 632 between an open position 628 (FIG. 42) and aclosed position 630 (FIG. 53). The cart door 620 may include one or moredoor latches 634 installed in a latch recess 636 (FIG. 53) for securingthe cart door 620 in the closed position 630 (FIG. 53). The cart door620 and/or end wall 618 may include one or more spacer device 730 (FIG.42) mounted to the interior surface 608 of the cart door 620. The spacerdevice 730 may comprise a spacer rib 732 that may be mounted to orextend outwardly from the interior surface 608 of the cart door 620 orend wall 618. The spacer device 730 may prevent blockage of asublimation path 758 (FIG. 54) of the cold gas 740 (FIG. 54) or carbondioxide gas 754 (FIG. 54) flowing downwardly. In this regard, the spacerdevice 730 may provide an air gap 734 (FIG. 55) between the food trays120 and the interior surface 608 of the end wall 618 and the cart door620 when the cart door 620 is in a closed position. Alternatively, thespacer device 730 may be located on the perimeter 122 of the food tray120. For example, the spacer device 730 may be configured as one or moreprotrusions (not shown) that may extend outwardly from the food tray 120perimeters 122 and maintain a spacing between the perimeters 122 and theinterior surfaces 608 of the side walls 612 and/or the interior surfacesof the cart door 620 when the cart door 620 is closed to provide airgaps between the cart door 620 and the food tray 120. The air gaps 734may facilitate the passage of the cold gas 740 or carbon dioxide gas 754sublimating from the refrigerant 188 (e.g., dry ice 752) containedwithin the refrigerant tray 700. In this manner, the cold gas 740 (e.g.,carbon dioxide gas 754) may flow downwardly from the refrigerant tray700 and circulate through the container interior 606 to cool thecontainer 604 air and maintain the food items at a safe temperature.

In an embodiment, the spacer device 730 (FIG. 55) may comprise one ormore spacer rib 732 provided in a suitable height 734 (FIG. 55) abovethe interior surface 608 of the cart door 620. For example, the spacerrib 732 may have a height 734 of from approximately 0.25 to 0.50 inchabove the interior surface 608 of the cart door 620 although the spacerrib 732 may be provided in heights larger or smaller than the 0.25 to0.50 height. In an embodiment, the spacer device 730 may be mounted tothe cart door 620 or integrally formed with the cart door 620. Evenfurther, the spacer device 730 may be mounted to the perimeter lips 122of the food trays 120. For example, the food trays 120 may includeprotrusions (not shown) that may extend laterally outwardly from theperimeter lips 122 of the food trays 120 for maintaining an air gap 734between the perimeters lip and the interior surface 608 of the cart door620 or end wall 618 of the container 604. It is also contemplated thatthe perimeter lips 122 of the food trays 120 may comprise holes (e.g.,FIGS. 14-15), apertures, or scallops (e.g., FIGS. 9-10) facilitate thecirculation of cold gas 740 or carbon dioxide gas 754 throughout thecontainer interior 606 (FIG. 53).

Referring to FIG. 44, shown is an embodiment of the refrigerant tray 700illustrating sublimation ports 728 formed in the refrigerant tray 700 toallow for passage of the cold gas 740 or carbon dioxide gas 754 (FIG.53). Although the sublimation ports 728 are shown formed along a bottomcorner edge of the refrigerant tray 700, the sublimation ports 728 maybe formed in any portion of the refrigerant tray 700. For example, thesublimation ports 728 may be formed in any location along the tray lowerwall 708. Furthermore, the sublimation ports 728 may be formed in otherlocations of the refrigerant tray 700 such as in the tray end walls 704or tray side walls 706. However, due to the tendency of the cold gas 740or carbon dioxide gas 754 (FIG. 53) to flow downwardly and based on thelocation of the air gaps 734 (FIG. 55) along the cart doors 620 (FIG.53), the sublimation ports 728 may be formed at one or both ends 702(FIG. 42) of the refrigerant tray 700. For example, the sublimationports 728 on the end 702 of the refrigerant tray 700 may be verticallyaligned with the air gaps 734 between the cart door 620 and the end-mostfood trays 120 (FIG. 42) such that the cold gas 740 or carbon dioxidegas 754 may flow downwardly through the air gaps 734. Although thesublimation ports 728 are shown as generally elongated slots in therefrigerant tray 700, the sublimation ports 728 may be provided in anyquantity, size, shape, or configuration. For example, the sublimationports 728 may be provided as holes, ducts, apertures or any otheropening configurations.

Referring to FIG. 45, shown is a top perspective view of the refrigeranttray 700 in a generally rectangularly shaped configuration having agenerally thin profile. The refrigerant tray 700 may have a generallyhollow rectangular shape and a relatively thin profile and may include atray lower wall 708 (FIG. 44), a portion of a tray upper wall 710 havinga lid 714, an opposing pair of tray side walls 706, and an opposing pairof tray end walls 704 although the refrigerant tray 700 may be providedin any size, shape or configuration. The lid 714 may be pivotable toallow access to the interior of the refrigerant tray 700 for installingand/or removing one or more dry ice pucks 750 from the refrigerant tray700.

The lid 714 may act as a sublimation rate control mechanism 712 whereinthe lid may be removed from the refrigerant tray 700 to increase theexposure of the refrigerant 188 (e.g., dry ice 752) to the relativelywarmer air of the container interior 606 (FIG. 43) and thereby increasethe rate of sublimation of the refrigerant 188. In a further embodiment,the refrigerant tray 700 may include one or more adjustable tray vents716 which may act as sublimation rate control mechanisms 712. Forexample, FIG. 45 illustrates a pair of adjustable tray vents 716 (shownin phantom) mounted on the lid 714 of the refrigerant tray 700. Each oneof the tray vents 716 may include an adjustable slider 718 forcontrolling the area of a vent opening 726 in the lid 714 and therebycontrol the flow of air from the container interior 606 into therefrigerant tray 700. Although shown as being mounted on the lid 714,one or more sublimation rate control mechanisms 712 such as tray vents716 may be mounted at any location on the refrigerant tray 700.

Referring still to FIG. 45, the sublimation rate control mechanism 712(e.g., the tray vents 716, the removable lid 714) may be used controlthe sublimation rate of the refrigerant 188 such that the airtemperature in the container interior 606 (FIG. 43) is maintained belowapproximately 7° C. or less. In a further embodiment, one or more of thesublimation rate control mechanisms 712 may be adjusted to maintain theair temperature within the container interior 606 at less thanapproximately 4° C. for a period of at least approximately 15 hours inan environment having an ambient air temperature of greater thanapproximately 29° C. as mentioned above. However, the sublimation ratecontrol mechanism 712 may be adjusted to maintain the container interior606 at any air temperature for any duration, without limitation.

Referring to FIG. 46, shown is a cross section of the refrigerant tray700 in an embodiment illustrating refrigerant 188 in the form of one ormore dry ice pucks 750 that may be mounted within the refrigerant tray700. In the embodiment shown, the dry ice puck 750 may comprise a slabof dry ice 752 formed in a relatively thin profile that may be sizedcomplementary to the refrigerant tray 700. The slab may comprise agenerally rectangular shape although other shapes and sizes arecontemplated. For example, the slab may be provided as one or moreblocks or cubes of dry ice 752 that may be loaded into the refrigeranttray 700. In a further embodiment, the refrigerant 188 may comprise dryice 752 in the form of a plurality of pellets of any size such asapproximately one-eight (⅛) inch or one-half (½) inch diameter pelletsalthough larger and smaller pellet sizes are contemplated. Providing thedry ice 752 in pellet form may result in a high sublimation raterelative to the sublimation rate that is achievable with the dry ice 752in slab form due to increased surface area of the pellets per unitvolume as compared to the surface are per unit volume of dry ice 752 inslab form.

Referring still to FIG. 46, the refrigerant tray 700 may include athermal isolator 756 that may be interposed between the refrigerant 188(e.g., the dry ice pucks 750) and the tray bottom wall 616 (FIG. 53) ofthe refrigerant tray 700 to thermally isolate the refrigerant 188 fromthe tray lower wall 708. The thermal isolator 756 may minimize orprevent heat conduction between the tray lower wall 708 and therefrigerant 188. In this regard, the thermal isolator 756 may preventfreezing of items on food trays 120 (FIG. 42) mounted directly below therefrigerant tray 700. It is contemplated that for food products (e.g.,ice cream) that must remain frozen (i.e., below 0° C.), the thermalisolator 756 may be omitted and food trays 120 containing such items maybe stored directly below the refrigerant tray 700. If the thermalisolator 756 is included with the refrigerant tray 700, the thermalisolator 756 is not limited to mounting on the tray lower wall 708 butmay be mounted at any location within the refrigerant tray 700. Forexample, the thermal isolator 756 may be mounted on the tray side walls706, the tray end walls 704 (FIG. 45), the lid 714 and/or the tray upperwall 710 to reduce the sublimation rate of the dry ice 752. The thermalisolator 756 may comprise an open cell foam and/or a closed cell foamsuch as polyurethane foam or other materials providing thermalinsulative capability. In an embodiment, the thermal isolator 756 may beconfigured as a portion of a vacuum insulated panel 648 (FIG. 13) havinga relatively high R-value such as between approximately 30 and 50 orother R-values.

Referring to FIGS. 47-48, shown is the container system 600 in anembodiment wherein the refrigerant tray 700 may include a tray chamfer707 extending along a tray side wall 706 of the refrigerant tray 700.The container 604 may have a container chamfer 607 formed complementaryto the tray chamfer 707 for controlling the orientation of therefrigerant tray 700 within the container interior 606. For example, thesublimation ports 728 in the refrigerant tray 700 may be limited to oneend of the refrigerant tray 700. By including the refrigerant tray 700with the tray chamfer 707 and providing the container 604 with thecontainer chamfer 607, the refrigerant tray 700 may be oriented suchthat the sublimation ports 728 are located at a desired location withinthe container interior 606. For example, the sublimation ports 728 maybe positioned adjacent to the cart door 620 (FIG. 53) when therefrigerant tray 700 is installed within the container interior 606. Inthis manner, cold gas 740 or carbon dioxide gas 754 (FIG. 53) exitingthe sublimation ports 728 may flow downwardly through the air gaps 734(FIG. 53) between the food trays 120 (FIG. 53) and the cart doors 620(FIG. 53) to cool the container interior 606. Although the refrigeranttray 700 is shown having a tray chamfer 707 and the container 604 isshown having a container chamfer 607, alternative configurations of therefrigerant tray 700 and the container 604 may be provided forcontrolling the orientation of the refrigerant tray 700 within thecontainer interior 606. For example, the refrigerant tray 700 and thecontainer 604 may be provided with a tongue- and groove (not shown)configuration or alternative arrangements for controlling theorientation of the refrigerant tray 700 within the container interior606.

Referring to FIG. 49, shown is a sectional view of the container 604illustrating a stopper mechanism 686 that may be mounted to thecontainer interior 606 for controlling the depth at which therefrigerant tray 700 (FIG. 47) is installed within the containerinterior 606. In an embodiment, the stopper mechanism 686 may comprise araised protrusion extending outwardly from the side wall 612 and/or thetray support 676. The stopper mechanism 686 may provide a means forcontrolling the position of the sublimation ports 728 (FIG. 47) withinthe container interior 606. For example, the stopper mechanism 686 maybe mounted such that when a refrigerant tray 700 is installed within thecontainer interior 606, the sublimation ports 728 are positionedadjacent to the cart door 620 (FIG. 53) to facilitate the flow of coldgas 740 or carbon dioxide gas 754 (FIG. 53) downwardly through the airgaps 734 (FIG. 53) between the food trays 120 (FIG. 53) and the cartdoor 620. One or more of the stopper mechanisms 686 may be located onone of the side walls 612 of the container 604 and/or tray support 676or on both side walls 612 of the container 604.

The stopper mechanism 686 may be a separate component that may bemechanically fastened or bonded to the side wall 612 and/or tray support676 or the stopper mechanism 686 may be integrated into the side wall612 and/or tray support 676. In embodiments, the refrigerant tray may beprovided in a length (not shown) that approximates the length of thecontainer interior 606. Such a long length of the refrigerant tray mayprovide additional volume for storing dry ice 752 as may be desired forextended durations. To facilitate the installation of a refrigerant trayhaving a long length (not shown), the tray side walls 706 (FIG. 47) maybe formed with a groove (not shown) for accommodating the stoppermechanism 686 such that a relatively long refrigerant tray may be slidover the stopper mechanism 686. In this manner, the container 604 mayaccommodate different lengths of the refrigerant tray 700 (FIG. 47)while maintaining a desired orientation of the refrigerant tray 700within the container interior 606.

Referring to FIGS. 50-51, shown is the refrigerant tray 700 having athermal regulator 757 mounted between the dry ice 752 and the thermalisolator 756. The thermal regulator 757 may comprise a layer ofthermally conductive material extending in a contiguous manner betweenthe tray side walls 706 and tray end walls 704. The thermal regulator757 may facilitate in-plane conduction of heat within the thermalregulator 757 and thereby facilitate a more uniform temperaturedistribution within the refrigerant tray 700 to extend the duration ofthe dry ice 752 before complete sublimation thereof. In a non-limitingembodiment, the thermal regulator 757 may be comprised of an aluminumsheet mounted between the dry ice 752 and the thermal isolator 756. Thealuminum sheet may facilitate a uniform rate of sublimation of the dryice 752. The thermal regulator 757, if included in the refrigerant tray700, may operate in conjunction with the sublimation rate controlmechanism 712. As indicated above, the sublimation rate controlmechanism 712 may comprise the lid 714 of the refrigerant tray 700 whichmay be installed or removed to control the exposure of the refrigerant188 to the air in the container 604. The sublimation rate controlmechanism 712 may also comprise tray vents 716 (FIG. 45) that mayoptionally be incorporated into the lid 714 or into other areas of therefrigerant tray 700.

For example, FIG. 50 illustrates the refrigerant 188 in the form of aplurality of dry ice pucks 750 that may be mounted on the thermalregulator 757. The dry ice pucks 750 may be provided as slabs or aspellets or in any other suitable form. If one of the dry ice pucks 750sublimates at a faster rate than the other dry ice pucks 750, thethermal regulator 757 may begin to warm up in the area of thefaster-sublimating dry ice puck 750. The heat in the area of thefaster-sublimating dry ice puck 750 may be conducted through the thermalregulator 757 toward relatively colder areas of the thermal regulator757. The conduction of heat through the thermal regulator 757 may slowthe sublimation rate of the faster-sublimating dry ice pucks 750. Inaddition, the slower-sublimating dry ice pucks 750 may then begin tosublimate at a rate that more closely matches the sublimation rate ofthe faster-sublimating dry ice pucks 750. In this regard, the thermalregulator 757 may act as a thermal battery as the dry ice pucks 750(e.g., slabs, pellets, etc.) reduce in size over time such that that thethermal regulator 757 may maintain a more uniform temperature of the dryice 752 over time. Although shown as being mounted to the thermalisolator 756, it is contemplated that the thermal isolator 756 may beomitted from the refrigerant tray 700 and the thermal regulator 757 maybe mounted directly to the tray lower wall 708. Although described aboveas an aluminum sheet, the thermal regulator 757 may be formed of anymetallic and/or non-metallic material providing a relatively high levelof in-plane thermal conductivity. The thermal regulator 757 may beincluded in any of the refrigerant tray 700 configurations disclosedherein.

Referring to FIG. 52, shown is the refrigerant tray 700 in an embodimentwherein the sublimation ports 728 may be located at one or more cornersof the refrigerant tray 700 and/or the sublimation ports 728 may be maybe provided in a small size relative to the larger size of thesublimation ports 728 illustrated in FIG. 44. In FIG. 52, by providingthe sublimation ports 728 in a relatively small size, cold gas 740 orcarbon dioxide gas 754 may be discharged from the sublimation ports 728at a relatively high velocity relative to the velocity of cold gas 740exiting the larger sublimation ports illustrated in FIG. 44. Arelatively high velocity of carbon dioxide gas 753 exiting thesublimation ports 728 of FIG. 52 may promote the entrainment of the coldgas 740 or carbon dioxide gas 754 within the air in the containerinterior 606. In this manner, the sublimation port 728 as shown in FIG.52 may improve mixing of the cold gas 740 or carbon dioxide gas 754 withthe air in the container 604 which may increase the cooling efficiencyof the container system 600.

Referring to FIG. 53, shown is an embodiment of the container 604 withone of the side walls 612 removed to expose the container interior 606.The cold gas 740 or carbon dioxide gas 754 is shown exiting thesublimation ports 728 of the refrigerant tray 700 and flowing downwardlyinto the container interior 606. A portion of the cold gas 740 or carbondioxide gas 754 may flow between the air gaps 734 between the food trays120 and the cart door 620. As was indicated earlier, the cart door 620may include one or more of the spacer ribs 732 or a functionallyequivalent spacer device 730 mounted to the cart door 620 and/or to thefood trays 120 for maintaining the air gap 734 between the food tray 120and the cart door 620. Also shown is a mid shelf 672 that may extendbetween the side walls 612 of the container 604 to improve the strengthand geometric stability of the galley cart 602. The mid shelf 672 mayinclude perforations through which the cold gas 740 or carbon dioxidegas 754 may flow as the cold gas 740 or carbon dioxide gas 754 flowsdownwardly and circulates within the container interior 606.

Referring to FIG. 54, shown is a side view of the container 604 with aside wall 612 removed to illustrate the sublimations paths 758 alongwhich the cold gas 740 or carbon dioxide gas 754 may flow. The cold gas740 or carbon dioxide gas 754 may exit the refrigerant trays 700 at thesublimation ports 728. Although illustrated as being mounted at theuppermost end of the container 604 directly underneath the top wall 614of the container 604. The refrigerant trays 700 may be mounted at anyone of the tray supports 676. Furthermore, although FIG. 54 illustratesa plurality of refrigerant trays 700 mounted at one vertical location,any number of refrigerant trays 700 may be mounted at one or morevertical locations. For example, one or more refrigerant trays 700 maybe mounted at the uppermost end of the container 604 and another set ofrefrigerant trays 700 may be mounted below the mid shelf 672 of thecontainer 604.

FIG. 54 also illustrates the passage of the cold gas 740 or carbondioxide gas 754 through the air gaps 734 between the food trays 120 andthe cart door 620 or end wall 618 of the container 604. In addition tothe downward flow of the carbon dioxide gas 754, the sublimation paths758 also include the generally laterally flow direction of cold gas 740or carbon dioxide gas 754 across the one or more food trays 120 withinthe container interior 606. As indicated above, the perimeter lips 122of the food trays 120 may include holes (e.g., FIGS. 14-15), apertures,or scallops (e.g., FIGS. 9-10) to facilitate the downward flow andcirculation of the cold gas 740 or carbon dioxide gas 754 within thecontainer interior 606.

Referring to FIG. 55, shown is a sectional view of the galley cart 602illustrating the air gap 734 provided by the spacer device 730 betweenthe interior surface 608 of the cart door 620 and the food trays 120that may be mounted within the galley cart 602. The spacer device 730 isshown as a spacer rib 732 mounted to the cart door 620 although thespacer device 730 may be provided in alternative shapes andconfigurations. The spacer rib 732 may be formed of metallic ornon-metallic material. For example, the spacer rib 732 may be formed ofaluminum that may be bonded to the cart door 620 or mechanicallyfastened to the cart door 620. Alternatively, the spacer rib 732 may beformed of polymeric material including thermoplastic material that maybe bonded or integrally formed with the cart door 620. The spacer rib732 may be provided in a height corresponding to the desired width ofthe air gap 734.

For example, the spacer rib 732 may be configured to provide an air gap734 having a width of from approximately 0.25 to 0.50 inch although thespacer rib 732 may be configured to provide an air gap 734 of any width.Although a single spacer device 730 is shown mounted to the cart door620, any number of spacer devices 730 may be provided. Furthermore, oneor more spacer device 730 may be positioned at any location within thecontainer interior 606 and are not limited to mounting along theapproximate vertical centerline of the cart door 620. For example, apair of spacer ribs 732 may be mounted to the cart door 620 with eachone of the spacer ribs 732 of the pair being mounted toward one of thevertical side edges of the cart door 620.

Referring to FIG. 56, shown is an embodiment of the container system 600wherein the food trays 120 are supported on a plurality of discretesupport knobs 609 extending laterally outwardly from the interiorsurfaces 608 of the side walls 612. The support knobs 609 may be locatedat spaced intervals along the interior surface 608 of the side walls612. In an embodiment, the support knobs 609 may be bonded to the innershell 650 of the side walls 612 and/or mechanically fastened to the sidewalls 612. Alternatively, the support knobs 609 may be integrally formedwith the inner shell 650. Advantageously, by configuring the traysupports 676 (FIG. 42) as support knobs 609 spaced along the side walls612, cold gas 740 (FIG. 54) and/or air within the container interior 606may pass vertically between the perimeter lips 122 of the food trays 120and the side walls 612. Also shown in FIG. 56 is an embodiment of themid shelf 672 having mid shelf cutouts or shelf scallops 673 formedalong the edges of the mid shelf 672 to facilitate the passage of coldgas 740 or carbon dioxide gas 754 and/or air between the mid shelf 672and the side walls 612. The mid shelf 672 may also include a pluralityof perforations through which the cold gas 740 or carbon dioxide gas 754and/or air may pass. The mid shelf 672 may include a horizontal portionintegral with vertical side tabs adhesively bonded and/or mechanicallyfastened to the side walls 612. As shown, the mid shelf cutouts (e.g.,shelf scallops 673) may be formed at spaced intervals between the sidetabs in each of opposing side edges of the mid shelf 672, and one ormore mid shelf cutouts (e.g., scallops 673) may be formed in each ofopposing end edges of the mid shelf 672. The support knobs 609, the airgap at each of the opposing ends, the side gaps along the opposing sidewalls 612, and the mid shelf cutouts collectively form a plurality ofuninterrupted vertically-oriented flow paths for the cold gas 740 alongthe opposing ends and along the side walls 612 between a top and abottom of the container interior 606.

Referring to FIG. 57, shown are the plurality of side gaps 736 formedbetween the support knobs 609, the food trays 120, and the interiorsurfaces 608 of the side walls 612. The side gaps 736 may enhancecirculation of the cold gas 740 (FIG. 54) or carbon dioxide gas 754(FIG. 54) and facilitate uniform cooling of the container interior 606.In addition, the side gaps 736 may enhance circulation of air within thecontainer interior 606. The container system 600 may also include one ormore spacer device 730 as described above. In an embodiment, the spacerdevice 730 may comprise the spacer rib 732 that may be mounted to one ormore of the cart doors 620 to maintain air gaps 734 between the foodtrays 120 and the cart doors 620. The combination of the air gaps 734and the side gaps 736 may facilitate a relatively rapid dispersion ofthe cold gas 740 or carbon dioxide gas 754 and/or air within thecontainer interior 606 and promote a uniform temperature distributionwithin the container interior 606.

Referring to FIG. 58, shown is a section view of the container 604illustrating the manner in which the food trays 120 may be supported bythe support knobs 609. The support knobs 609 may have a concave uppersurface such that the perimeter lip 122 of the food tray 120 may bebiased away from the side wall 612 under the weight of the food tray120. In this manner, the concave shape of the support knobs 609 maycause the food trays 120 to be generally centered within the width ofthe container interior 606 such that side gaps 736 (FIG. 57) may beformed between the food trays 120 and the side walls 612 on both sidesof the container interior 606. Although shown as having a generallytriangular cross-sectional shape with concave sides, the support knobs609 may be provided in alternative sizes, shapes, and configurations,without limitation. An advantage provided by the support knobs 609 is areduction in thermal conductance between the food trays 120 and the sidewalls 612 relative to the thermal conductance that may occur wherein thetray supports 676 extend along a substantial length of the side walls612 as illustrated in FIG. 42.

Referring to FIGS. 59-60, shown is an embodiment of the container system600 (FIG. 59) having one or more refrigerant trays 700 (FIG. 60) formedwithout openings such that the cold gas 740 (FIG. 54) or carbon dioxidegas 754 (FIG. 54) may be generally confined within the refrigerant tray700. In such an embodiment, the container system 600 may rely on one ormore convection cycles 764 (FIG. 59) that may occur within the containerinterior 606. In this regard, the cold gas 740 or carbon dioxide gas 754inside the refrigerant tray 700 may cool the tray side walls 706 (FIG.60), the tray end walls 704 (FIG. 60), the tray lower wall 708 (FIG.60), the lid 714 (FIG. 60), and/or the tray upper wall 710 (FIG. 60)such that contact of the air with the refrigerant tray 700 causes theair to cool resulting in cold air 760 (FIG. 59) that may sink within thecontainer 604. The sinking cold air 760 may displace warm air 762 (FIG.59) in the container 604 causing the warm air 762 to rise and come intocontact with the refrigerant tray 700. The combination of the air gaps734 (FIG. 59) between the food trays 120 (FIG. 59) and the cart doors620 (FIG. 59) and the side gaps 736 (FIG. 57) between the food trays 120and the side walls 612 may provide passageways for the sinking cold air760 and the rising warm air 762.

The warm air 762 may be warm in the sense that the warm air 762 iscolder that the ambient air outside of the container 604 but warmer thanthe cold air 760 that is sinking within the container 604 due to contactwith the refrigerant trays 700. The sinking of the cold air 760 and therise of the warm air 762 within the container interior 606 may representone or more convection cycles 764 (FIG. 59) that may occur within thecontainer interior 606 and which may maintain the container interior 606below a desired temperature. For example, any one of the embodiments ofthe container 604 shown in FIGS. 1, 42, 47, 53, 56, 61 and 68 may becombined with one or more refrigerant trays 700 (FIG. 60) which maycooperatively maintain the air temperature within the container interior606 at less than approximately 7° C. (approximately 45° F.) or lower forextended periods of time such as up to approximately 15 hours or longerwhen the container 604 is in an environment having an ambient airtemperature of greater than up to approximately 29° C. (approximately84° F.) or higher temperatures. Advantageously, by omitting openings inthe refrigerant tray 700, the cold gas 740 (e.g., FIG. 45) or carbondioxide gas 754 (e.g., FIG. 45) may be generally confined within therefrigerant tray 700 which may slow the sublimation rate and extend theuseful life of the refrigerant 188 or dry ice 752 within the refrigeranttray 700. In an embodiment, the refrigerant tray (not shown) may beprovided in a length that approximates the length of the containerinterior 606 and containing refrigerant 188 or dry ice 752 alongdistributed along the length of the refrigerant tray such that a singleconvection cycle (not shown) may occur within the container interior 606as air flows (not shown) along the length of the exterior of therefrigerant tray.

Referring to FIG. 61, shown is a perspective illustration of anembodiment of the container 604. As indicated earlier, the container 604may include vacuum insulated panels 648 having a relatively high R-valuefor insulating the container 604. The vacuum insulated panels 648 may besandwiched between an inner shell 650 and an outer shell 652 to protectthe integrity of the vacuum insulated panels 648 and to extend theoperating life of the container 604 and increase the insulativecapability of the container 604. As indicated above, the refrigeranttray 700 may be implemented with the container 604 to cooperativelymaintain the air temperature within the container interior 606 at lessthan approximately 7° C. for a period of at least approximately 15hours. The combination of the refrigerant tray 700 (e.g., FIGS. 44, 54,60) and the insulated container 604 may further result in a container604 that may maintain the air temperature within the container interior606 at between approximately 1° C. and 4° C. for a period of at leastapproximately 15 hours when the container 604 is an environment havingan ambient air temperature of greater than approximately 29° C. Asindicated above, the construction of the container 604 in variousembodiments as described below may be such that the refrigerant tray 700and the container 604 may cooperatively limit heat gain into thecontainer interior 606 (FIG. 62) to less than approximately 100 Btu/hourin an environment having an ambient temperature of greater thanapproximately 29° C.

Referring to FIG. 62, shown is an embodiment of an inner shell 650 thatmay be included with the container 604. The inner shell 650 may beformed of metallic or non-metallic material. For example, the innershell 650 may be formed of polymeric material including thermoplasticmaterial of a suitable thickness (e.g., 0.050 inch). The thermoplasticmaterial may comprise acrylic-polyvinyl chloride (PVC) sheet materialcommercially available as Kydex™ sheet material from Kydex, LLC ofBloomsburg, Pa. However, the inner shell 650 may be formed of otherthermoplastic materials which may be thermoformed or vacuum formed intothe desired shape. For example, one or more ribs 670 may be thermoformedor vacuum formed into the inner shell 650. The ribs 670 may function asthe tray supports 676 for supporting food trays 120 (FIG. 42) and/orcold trays (e.g., FIG. 1) and/or refrigerant trays 700 (FIGS. 44, 54,60) within the container interior 606.

Alternatively, separate tray rails 678 may be formed of metallic ornon-metallic material and may be adhesively bonded and/or mechanicallyfastened to the inner shell 650. The inner shell 650 may also be formedof metallic material such as aluminum or other lightweight metallicmaterial with relatively high ductility to provide a durable liner forthe container interior 606 to protect the vacuum insulated panels 648against punctures as food trays 120 are continuously placed inside ofand removed from the container interior 606. In addition, the innershell 650 may be formed of thermosetting material including graphiteepoxy. The thermosetting and/or thermoplastic materials for the innershell 650 may optionally include fibrous reinforcing material forincreasing the strength and durability of the inner shell 650.

Referring still to FIG. 62, the inner shell 650 may be fabricated inshell sections 660 to simplify manufacture. For example, although notshown in FIG. 62, the inner shell 650 may be formed as four (4) separateshell sections 660 corresponding to one or more portions of the sidewalls 612, the top wall 614, and the bottom wall 616 of the container604. The shell sections 660 may be joined to one another. In thisregard, the container 604 may include a plurality of stiffener rings 666that may be mounted to the inner shell 650 to interconnect the shellsections 660. The stiffener rings 666 may extend along the side walls612, top wall 614, and bottom wall 616 to encircle the inner shell 650and interconnect the inner and outer shells 650, 652 to one another. Thestiffener rings 666 may improve the structural stiffness and stabilityof the container 604 and may maintain the generally orthogonal orrectangular shape of the container 604 when side loads are applied tothe container 604.

The stiffener rings 666 may be formed of metallic or non-metallicmaterial and which preferably has relatively high strength andstiffness. In an embodiment, the stiffener rings 666 may be formed ofgraphite thermoplastic or thermosetting material or fiberglass. Thestiffener rings 666 may also be formed of lightweight high strengthmetallic material such as aluminum, titanium, or other metallicmaterials. Although FIG. 62 illustrates three (3) of the stiffener rings666 located on the ends and at the center of the container 604, anynumber of stiffener rings 666 may be provided and may be positioned atany location on the container 604.

In FIG. 62, the mid shelf 672 may be assembled with the inner shell 650to interconnect the side walls 612. The mid shelf 672 may increase thestrength and stiffness of the container 604 by interconnecting the sidewalls 612 and may include perforations to facilitate the circulation ofcold gas 740 (FIG. 54) or carbon dioxide gas 754 (FIG. 54) within thecontainer interior 606. In an embodiment, the mid shelf 672 may beformed of a metallic or non-metallic material. For example, the midshelf 672 may be formed of aluminum in a relatively small thickness suchas 0.050 inch. The mid shelf 672 may be adhesively bonded to the sidewalls 612 and/or mechanically fastened to the side walls 612.

Referring to FIG. 63, shown is an embodiment of the inner shell 650 anda plurality of vacuum insulated panels 648 that may be mounted betweenthe inner shell 650 and the outer shell 652 (FIG. 64). The vacuuminsulated panels 648 may have a cross section similar to that which isillustrated in FIG. 13 wherein the vacuum insulated panels 648 maycomprise a core 38 (FIG. 13) such as a foam core that may be surroundedby face sheets 36 (FIG. 13). The face sheets 36 may be formed of sealedmetallic and/or polymeric film or foil that may be applied to opposingside surfaces of the core 38 and to the edging 646 of the core such thatthe vacuum insulated panel 648 is substantially air tight.Advantageously, the vacuum insulated panels 648 may minimize oreliminate thermal bridging from an exterior of the container 604 to thecontainer interior 606.

The vacuum insulated panels 648 (FIG. 63) may advantageously be providedin a relatively small thickness such that the geometry of the containerinterior 606 may be maintained within industry standards such thatstandard-size food trays 120 (FIG. 42) and galley storage bins (notshown) may be used with the container 604 embodiments disclosed herein.For example, the vacuum insulated panels 648 for the top wall 614 andthe bottom wall 616 may have a thickness in the range of fromapproximately 0.20 to 1.0 inch and preferably in a thickness ofapproximately 0.25 to 0.38 inch. The vacuum insulated panels 648 for theside walls 612 may also have a thickness in the range of fromapproximately 0.20 to 1.0 inch and preferably in a thickness ofapproximately 0.38 to 0.50 inch. The vacuum insulated panels 648 for thecart doors 620 (FIG. 67) may be provided in a thickness in the range offrom approximately 0.25 to 0.50. Furthermore, the vacuum insulatedpanels 648 for the cart doors 620 may be layered against one another toprovide increased insulative capability for the cart doors 620. Forexample, the cart door 620 may include two (2) layers of vacuuminsulated panels 648 each having a thickness of approximately 0.25 inchand which may be adhesively bonded to one another such as by usingstructural adhesive tape 642 as shown in FIG. 67 and described ingreater detail below.

FIG. 63 illustrates the vacuum insulated panels 648 divided intosections for installation to each one of the side walls 612, the topwall 614, and the bottom wall 616. The vacuum insulated panels 648 maybe installed within the stiffener rings 666 to increase the strength andstiffness of the container system 600. In an embodiment, the container604 may have only two (2) stiffener rings 666 located on opposing endsof the container 604. The container 604 may be configured such that asingle vacuum insulated panel 648 may be installed on each one of theside walls 612, the top wall 614, and the bottom wall 616. The vacuuminsulated panels 648 may be attached to the inner shell 650 such as byadhesively bonding to the inner shell 650 and/or mechanically fixing thevacuum insulated panels 648 in position against the inner shells. In anembodiment, the vacuum insulated panels 648 may be bonded to the innershell 650 with structural adhesive tape 642 such as VHB™ (very highbond) Structural Glazing Tape 642 commercially available from the 3M™Company of Maplewood, Minn. However, the vacuum insulated panels 648 maybe bonded to the inner shell 650 with any suitable structural adhesive.

Referring to FIG. 64, shown is an embodiment of the outer shell 652which may be formed as separate shell sections 660 that may be assembledtogether. The shell sections 660 may be formed as an opposing pair ofside walls 612 and may include portions of the top wall 614 and portionsof the bottom wall 616. A shell section 660 may also be formed for thetop wall 614 and another shell section 660 may be formed for the bottomwall 616. The longitudinal edges of each one of the shell sections 660may include a longitudinal flange 662. The shell sections 660 may beassembled by mechanically attaching and/or adhesively bonding thelongitudinal flanges 662 to one another. Referring briefly to FIG. 66, aplurality of C clips 664 may be installed at spaced intervals along thelongitudinal flanges 662 to mechanically interconnect the shell sections660. The C clips 664 may stabilize the joint between the longitudinalflanges 662 during curing of adhesive between the longitudinal flanges662. Although the outer shell 652 is illustrated and described ascomprising one or more shell sections 660, the outer shell 652 and/orthe inner shell 650 may be formed as a unitary structure of metallicand/or non-metallic material.

Referring still to FIG. 64, the outer shell 652 may be formed ofmetallic or non-metallic material. For example, the outer shell 652 maybe formed of thermoplastic or thermosetting material similar to thematerials that may be used for forming the inner shell 650. The outershell 652 may be provided in a thickness range of from approximately0.030 to 0.125 inch although the outer shell 652 may be provided inother thickness ranges. In an embodiment, the outer shell 652 may beformed of metallic material such as metallic or non-metallic honeycombpanel or sheeting such as aluminum honeycomb panel. The honeycomb panelmay have increased stiffness relative to standard homogenous metallicand non-metallic sheeting. In this regard, the honeycomb panel mayfunction as a structural outer panel 654 for the container 604 and mayprovide improved strength and geometric stability to the container 604and protection against impacts against the exterior surface 610 that mayotherwise damage or result in piercing of the vacuum insulated panel 648beneath the outer shell 652. The outer shell 652 may optionally includea decorative laminate that may be adhesively bonded to the exteriorsurface 610 of the outer shell 652.

Referring to FIG. 65, shown is the inner shell 650 and the vacuuminsulated panels 648 assembled to the outer shell 652. The outer shell652 sections may be bonded together along the longitudinal flanges 662using a plurality of the C clips 664 installed at spaced intervals tomechanically interconnect the longitudinal flanges 662. The vacuuminsulated panels 648 may be bonded to the outer shell 652 usingstructural adhesive tape 642 (FIG. 67). The vacuum insulated panels 648(FIG. 63) may also be mechanically connected to the inner shell 650 andthe outer shell 652. The assembly of the inner and outer shells 650, 652with the vacuum insulated panels 648 may be further strengthened withthe addition of a pair of door frames 626 on opposing ends of thecontainer 604.

Referring still to FIG. 65, the door frames 626 may be interconnected bymeans of one or more tie rods 684. For example, each one of thelongitudinal corners of the container 604 may include a tie rod 684extending between the door frames 626. The tie rods 684 may beconfigured to be removable to allow for disassembly of the container604. The vacuum insulated panels 648 (FIG. 63) may be non-permanentlyattached to the inner and/or outer shells 650, 652 to facilitate removaland replacement of the vacuum insulated panels 648.

Referring to FIG. 66, shown are the C clips 664 that may be installedalong the longitudinal flanges 662 to mechanically interconnect theshell sections 660. The C clips 664 may stabilize the joint between thelongitudinal flanges 662 during bonding of the longitudinal flanges 662.The C clips 664 may also provide redundancy for the connection of thelongitudinal flanges 662 and prevent peeling of an adhesive bond betweenthe longitudinal flanges 662.

Referring to FIG. 67, shown is a cross section of an embodiment of thecart door 620 in sealing relation with one of the door frames 626 of thecontainer 604. Although the cart door 620 is shown in the framed door624 configuration in FIG. 67, the cart door 620 may be provided in anoverlapping door 622 configuration as shown in FIG. 71 and described ingreater detail below. Alternatively, the cart door 620 may be providedin a combination framed door 624 configuration and overlapping door 622configuration. Advantageously, the framed door 624 configuration asshown in FIG. 67 may increase the structural stability of the container604 wherein the framed door 624 may interface with the door frame 626mounted at each end of the container 604. The door frame 626 may allowthe cart door 620 to act as a shear web to improve the overall stiffnessof the container 604.

Referring still to FIG. 67, the cart door 620 may be sealed against thedoor frame 626 by means of a door seal 638. The door seal 638 may beformed of a foam material such as closed cell or open cell foam or othersuitable sealing material. The cart door 620 may include one or morelayers of the vacuum insulated panels 648. For example, the cart door620 may include two (2) layers of the vacuum insulated panels 648sandwiched between the inner and outer shells 650, 652 to improve theinsulative capability of the cart door 620. Foam edging 640 may beinstalled along a perimeter edge of the cart door 620. The foam edging640 may comprise a polyetherimide (PEI) thermoplastic material or othersuitable edging material. The foam edging 640 may be bonded to the innersurface of the outer shell 652 such as by spray foaming for insulativebonding of the foam edging 640 to the inner surface of the outer shell652 or mechanical fasteners 674 may be installed through the outer shell652 and into the foam edging 640. An edge sealant/gap filler 644 may beinstalled between the edges of the vacuum insulated panels 648 and thefoam edging 640 to improve the dimensional stability of the vacuuminsulated panels 648. Likewise, foam edging 640 may be installed along aperimeter edge of the side walls 612, top wall 614 (FIG. 66), and bottomwall 616 (FIG. 62) with the optional installation of edge sealant/gapfiller 644 between the edges of the vacuum insulated panels 648 and thefoam edging 640.

Referring to FIGS. 68-70, shown is an embodiment of the container 604that may be assembled using angle members and/or channel members tointerconnect the side walls 612, the top wall 614 and the bottom wall616 of the container 604. The side walls 612, top wall 614 and bottomwall 616 may each be comprised of one or more vacuum insulated panels648 sandwiched between inner and outer shells 650, 652 as describedabove. FIGS. 69-70 illustrate edging 646 members configured as metallic(e.g., aluminum) or non-metallic angle of suitable thickness (e.g.,0.030 to 0.090 inch) for interconnecting the side panels to the top wall614 and the bottom wall 616 along the longitudinal edges (i.e.,extending between the cart doors 620) of the container 604. Edging 646may also be applied to vertical edges of the container 604 (i.e.,extending between the top and bottom walls 614, 616) of the container604.

Caps 656 may be installed at each end of the container 604 tointerconnect the top and bottom wall 614, 616 to the side walls 612. Thecaps 656 and edging 646 at each end of the container 604 may form a doorframe 626 for the cart door 620. The edging 646 and the caps 656 may bebonded and/or mechanically fastened to the side walls 612, top wall 614and the bottom wall 616. In FIG. 70, the lower chassis 682 comprisingthe casters 680 and the wheel and brake set (not shown) may be bondedand/or mechanically fastened to the bottom wall 616 of the container604. A trim ring 658 may be mechanically fastened to the top wall 614.In FIG. 69, at the top wall 614, the trim ring 658 may optionally beintegrated with the caps 656, the edging 646, and the top wall 614 tosimplify assembly and disassembly for repair and replacement ofcomponents of the container 604.

Referring to FIG. 71, shown is a cross section of the cart door 620 inoverlapping relation to the side wall 612 of the container 604 of FIG.68. The cart door 620 may include two (2) or more vacuum insulatedpanels 648 sandwiched between inner and outer shells 650, 652 althoughthe cart door 620 may include a single vacuum insulated panel 648between the inner and outer shells 650, 652. A door seal 638 may beinstalled between the cart door 620 and the edging 646 along the sidewall 612. Foam edging 640 and edge sealant/gap filler 644 may beinstalled similar to the configuration described above for the cart door620 arrangement of FIG. 67. FIG. 71 further illustrates the edging 646applied to the side walls 612 and to the cart door 620. The vacuuminsulated panels 648 may be bonded to the inner and outer shell 650, 652using a structural adhesive tape 642 and/or mechanical fasteners 674(not shown).

Referring to FIG. 72, shown is a cross bar 674 mounted within the sidewall 612 for attaching the mid shelf 672 to the side wall 612. The crossbar 674 may be formed of a substantially rigid foam element such aspolyetherimide (PEI) thermoplastic foam or other suitable material. Thecross bar 674 may extend longitudinally between the opposing cart doors620 (FIG. 68) of the container 604 and may be positioned between avacuum insulated panel 648 located above the cross bar 674 and a vacuuminsulated panel 648 located below the cross bar 674. The cross bar 674may be aligned with the stiffener panel and may provide structurallystability to the side wall 612 for securing the mid shelf 672 to theside wall 612. The mid shelf 672 may be bonded and/or mechanicallyfastened to the side walls 612 at the location of the cross bar 674.

Referring to FIG. 73, shown is a flow chart of a method 800 for coolingthe interior 606 of a container 604 (e.g., FIGS. 42, 53, 61, 68) such asa galley cart 602 (e.g., FIGS. 42, 53, 61, 68). Advantageously, themethod for cooling the container interior 606 may be performed in apassive manner without reliance on a mechanical refrigeration system(not shown).

Step 802 of the method 800 of FIG. 73 may comprise loading one or morerefrigerant trays 700 (e.g., FIG. 45) with refrigerant 188 such as a dryice puck 750 (FIG. 45) comprising dry ice 752 pellets and/or dry ice 752in slab form. Step 802 may comprise mounting one or more refrigeranttrays 700 within the container interior 606. For example, FIGS. 42-43illustrate the refrigerant tray 700 being mounted within the container604 above a food tray. The refrigerant tray 700 may include one or moreof the sublimation ports 728 such as the sublimation ports 728 locatedat one or both of the ends 702 of the refrigerant tray 700. However, therefrigerant tray 700 may be provided without sublimation ports 72 asshown in FIG. 60.

Step 804 of the method 800 of FIG. 73 may comprise thermally isolatingthe refrigerant 188 (FIG. 46) from the refrigerant tray 700 (FIG. 46).For example, FIG. 46 illustrates a thermal isolator 756 mounted betweenthe dry ice puck 750 and the tray lower wall 708 of the refrigerant tray700. Step 804 may also comprise minimizing heat conduction between thetray lower wall 708 and the refrigerant 188 using the thermal isolator756 to prevent the freezing of items that are mounted directly below therefrigerant tray 700.

Step 806 of the method 800 of FIG. 73 may comprise sublimating therefrigerant 188 (e.g., dry ice 752—FIG. 45) to produce cold gas 740(FIG. 45). If the refrigerant 188 is provided as dry ice 752, the dryice 752 may sublimate from solid carbon dioxide directly to gaseouscarbon dioxide 754 when the temperature of the dry ice 752 exceeds −78°C. (approximately −109° F. at one atmosphere).

Step 808 of the method 800 of FIG. 73 may comprise regulating thesublimation rate of the refrigerant 188. In an embodiment, thesublimation rate may be regulated by adjusting the tray vents 716 (FIG.45) that may be mounted to the lid 714 of the refrigerant tray 700 asshown in FIG. 45. The tray vents 716 may be adjusted to regulate theamount of air that can pass through the tray vents 716 and enter therefrigerant tray 700 interior to regulate the exposure of therefrigerant 188 to air within the container interior 606 (FIG. 53). Inthis regard, the tray vents 716 may be opened and closed to respectivelyincrease and decrease exposure of the refrigerant 188 (e.g. dry ice 752)to the warmer air temperature within the container interior 606resulting in a respective increase and decrease in the sublimation rate.

Step 810 of the method 800 of FIG. 73 may comprise passing the cold gas740 (FIG. 53) or carbon dioxide gas 754 (FIG. 53) through thesublimation ports 728 (FIG. 53) of the refrigerant tray 700 (FIG. 53)and into the container interior 606 (FIG. 53). For example, FIGS. 53-54illustrate the cold gas 740 or carbon dioxide gas 754 flowing generallydownwardly out of the sublimation ports 728 and into the containerinterior 606. The cold gas 740 or carbon dioxide gas 754 may flowgenerally downwardly due to the cold temperature of the cold gas 740 orcarbon dioxide gas 754 relative to the air within the container interior606 and due to the high density of cold gas 740 or carbon dioxide gas754 relative to the density of air.

Step 812 of the method 800 of FIG. 73 may comprise maintaining air gaps734 (FIGS. 53-54) between the interior surface 608 of the container 604and one or more of the food trays 120 disposed adjacent to the interiorsurface 608. FIG. 55 illustrates the air gap 734 between the interiorsurface 608 of the cart door 620 and the food trays 120. The air gap 734may be maintained with the aid of a spacer device 730 such as the spacerrib 732 mounted to the cart door 620 as illustrated in FIG. 55. In anembodiment of the container 604 shown in FIG. 57, side gaps 736 may beformed between the food trays 120 and the interior surfaces 608 of theside walls 612 to facilitate the vertical movement of cold gas 740 orcarbon dioxide gas 754 (FIG. 45) and/or air within the containerinterior 606.

Step 814 of the method 800 of FIG. 73 may comprise passing the cold gas740 or carbon dioxide gas 754 (FIGS. 53-54) through the air gaps 734.FIGS. 53-54 illustrate the cold gas 740 or carbon dioxide gas 754flowing downwardly and between the air gaps 734 between the food trays120 and the cart door 620. The cold gas 740 or carbon dioxide gas 754may flow along one or more sublimation paths 758. The sublimation paths758 may extend through the air gaps 734. In an embodiment of thecontainer system 600 wherein the refrigerant trays 700 (FIG. 60) may bedevoid of openings, the container interior 606 (FIG. 59) may be cooledby contact of the air with exterior surfaces of the refrigerant tray 700as described above. The cooled or cold air 760 may then sink as shown inFIG. 59 and may displace warm air 762 which may rise and come intocontact with the refrigerant tray 700 such that the cold air 760 and thewarm air 762 may form one or more convection cycles 764 within thecontainer interior 606 as described above. The cold air 760 (FIG. 59)and the warm air 762 (FIG. 59) may pass through the air gaps 734 (FIG.57) and the side gaps 736 (FIG. 57).

Step 816 of the method 800 of FIG. 73 may comprise maintaining the airtemperature within the container interior 606 (FIGS. 53, 54, 59) at lessthan a predetermined temperature. For example, the cold air 762 (FIG.59) and/or the cold gas 740 (FIG. 54) or carbon dioxide gas 754 (FIG.54) flowing within the container interior 606 may maintain the airtemperature within the container interior 606 at less than approximately7° C. and, more preferably, at a temperature of less than approximately4° C. for a period of up to approximately 15 hours in an environmenthaving an ambient air temperature of up to approximately 29° C. orhigher. Advantageously, the container 604 may be constructed to providea high level of thermal insulative capability which may facilitate thepassive cooling of the container interior 606 to a relatively lowtemperature for extended durations without the aid of a mechanicalrefrigeration system (not shown).

Further advantages provided by embodiments of the passively-cooledcontainer systems 600 (e.g., FIGS. 42, 53, 56, 59, 61, 68) disclosedherein include an increase in the flexibility of locations within anaircraft cabin (not shown) where galley carts 602 (e.g., FIGS. 42, 53,56, 59, 61, 68) may be stored. By reducing or eliminating the need for adedicated mechanical refrigeration system (not shown) as conventionallyused for chilling galley carts stored in an aircraft galley (not shown),galley carts 602 chilled using the presently disclosed cold trays (e.g.,FIG. 6) and/or refrigerant trays 700 (e.g., FIGS. 47, 52, 60) may bestored at a wider variety of locations within the aircraft cabin whichmay increase the options for configuring the aircraft cabin. In thissame regard, the elimination of a conventional mechanical refrigerationsystem for the galley carts 602 eliminates the need to provide space forducting (not shown) for supplying and returning air from a mechanicalrefrigeration system to the galley carts 602. The elimination of suchducting from the aircraft cabin by using the embodiments disclosedherein provides the potential for the adding an additional row ofrevenue-generating passenger seats. In addition, the elimination ofconventional mechanical refrigeration systems for chilling galley carts602 may also reduce noise output and heat output of such mechanicalrefrigeration systems and may result in an increase in comfort forpassengers and crew. A further advantage provided by the embodimentsdisclosed herein includes an improvement in aerodynamic performance ofthe aircraft due to a reduction in the amount of outside air that mustbe drawn through an opening (not shown) on the exterior surface (notshown) of the aircraft for cooling a mechanical refrigeration systemdedicated for chilling galley carts 602.

Additional modifications and improvements of the present disclosure maybe apparent to those of ordinary skill in the art. Thus, the particularcombination of parts described and illustrated herein is intended torepresent only certain embodiments of the present disclosure and is notintended to serve as limitations of alternative embodiments or deviceswithin the spirit and scope of the disclosure.

What is claimed is:
 1. A container system, comprising: a containerhaving opposing side walls and a container interior, each of theopposing side walls including a plurality of discrete support knobsspaced along a horizontal direction of the side walls and along avertical direction of the side walls; a mid shelf extending horizontallybetween the side walls and including a horizontal portion integral withvertical side tabs non-movably attached to the side walls by adhesivebonding and/or mechanical fastening, the horizontal portion includingperforations and having a plurality of mid shelf cutouts formed atspaced intervals between the side tabs in each of opposing side edges ofthe mid shelf and one or more mid shelf cutouts formed in each ofopposing end edges of the mid shelf, the mid shelf configured toincrease the strength and stiffness of the container, the mid shelfpositioned within the container such that at least some of the pluralityof support knobs are located above the mid shelf and at least some ofthe plurality of support knobs are located below the mid shelf; a pairof refrigerant trays each being configured to contain a refrigerantproducing a cold gas upon sublimation and having sublimation portsformed on opposing ends of the refrigerant tray; each refrigerant traybeing configured to be slidably inserted into and positioned within thecontainer interior above one or more food trays; each refrigerant trayhaving a vent opening to allow a flow of air from the container throughthe vent opening and downwardly over the refrigerant in a manner suchthat the cold gas flows out of the sublimation ports and downwardly intoa general center of the container interior and downwardly through theperforations in the mid shelf and through an air gap at each one of theopposing ends of the container between one of the one or more food traysand a cart door or end wall of the container and through side gapsformed between each of the one or more food trays and the side walls;and wherein the support knobs, the air gap at each of the opposing ends,the side gaps along the opposing side walls, and the mid shelf cutoutscollectively form a plurality of uninterrupted vertically-oriented flowpaths for the cold gas along the opposing ends and along the side wallsbetween a top and a bottom of the container interior.
 2. The containersystem of claim 1 further comprising: a spacer device configured tomaintain the air gap between the one of the one or more food trays andan interior surface of the container at each one of the opposing ends ofthe container.
 3. The container system of claim 2 wherein: the spacerdevice is mounted to an interior surface of the cart door; and thespacer device being configured to maintain the air gap between the oneof the one or more food trays and the cart door when the cart door is ina closed position.
 4. The container system of claim 1 wherein: at leastone of the refrigerant trays includes a thermal isolator configured tobe mounted between the refrigerant and a tray lower wall of therefrigerant tray.
 5. The container system of claim 1 wherein: at leastone of the refrigerant trays includes a thermal regulator configured tobe mounted between the refrigerant and a tray lower wall of therefrigerant tray.
 6. The container system of claim 1 wherein: the pairof refrigerant trays and the container are configured to cooperativelymaintain an air temperature within the container interior at less thanapproximately 4° C. for a period of at least approximately 15 hours inan environment having an ambient air temperature of greater thanapproximately 29° C.
 7. The container system of claim 1 wherein: thepair of refrigerant trays and the container are configured tocooperatively limit heat gain into the container interior to less thanapproximately 200 Btu/hour in an environment having an ambienttemperature of greater than approximately 29° C.
 8. The container systemof claim 1 wherein: the container is comprised of a plurality of vacuuminsulated panels at least partially enclosing the container interior. 9.The container system of claim 8 wherein: at least one of the vacuuminsulated panels is interposed between an inner shell and an outershell; and at least one of the inner shell and the outer shell beingcomprised of at least one of the following: honeycomb panel, polymericsheet, metallic sheet.
 10. An aircraft, comprising: a passively-cooledmovable container having opposing side walls and a container interiorand being configured to contain a plurality of food trays, each of theopposing side walls including a plurality of discrete support knobsspaced along a horizontal direction of the side walls and along avertical direction of the side walls; a mid shelf extending horizontallybetween the side walls and including a horizontal portion integral withvertical side tabs non-movably attached to the side walls by adhesivebonding and/or mechanical fastening, the horizontal portion includingperforations and having a plurality of mid shelf cutouts formed atspaced intervals between the side tabs in each of opposing side edges ofthe mid shelf and one or more mid shelf cutouts formed in each ofopposing end edges of the mid shelf, the mid shelf configured toincrease the strength and stiffness of the container, the mid shelfpositioned within the container such that at least some of the pluralityof support knobs are located above the mid shelf and at least some ofthe plurality of support knobs are located below the mid shelf; a pairof refrigerant trays each being configured to contain a refrigerantproducing a cold gas upon sublimation and being configured to beslidably inserted into and positioned within the container interiorabove at least one of the food trays and having sublimation ports formedon opposing ends of the refrigerant tray; the container being formed ofa plurality of vacuum insulated panels enclosing the container interior;each refrigerant tray having a vent opening to allow a flow of air fromthe container into the refrigerant tray through the vent opening anddownwardly over the refrigerant in a manner such that the cold gas flowsout of the sublimation ports and downwardly into a general center of thecontainer interior and downwardly through the perforations in the midshelf and through air gaps at the opposing ends of the container betweenthe food trays and a cart door or end wall of the container and throughside gaps formed between each of the one or more food trays and the sidewalls; and wherein the support knobs, the air gap at each of theopposing ends, the side gaps along the opposing side walls, and the midshelf cutouts collectively form a plurality of uninterruptedvertically-oriented flow paths for the cold gas along the opposing endsand along the side walls between a top and a bottom of the containerinterior.
 11. A method of refrigerating an interior of a container,comprising the steps of: slidably inserting a pair of refrigerant traysinto a container interior of a container having opposing side walls,each of the opposing side walls including a plurality of discretesupport knobs spaced along a horizontal direction of the side walls andalong a vertical direction of the side walls, the container including amid shelf extending horizontally between the side walls and including ahorizontal portion integral with vertical side tabs non-movably attachedto the side walls by adhesive bonding and/or mechanical fastening, thehorizontal portion including perforations and having a plurality of midshelf cutouts formed at spaced intervals between the side tabs in eachof opposing side edges of the mid shelf and one or more mid shelfcutouts formed in each of opposing end edges of the mid shelf, eachrefrigerant tray having sublimation ports formed on opposing ends of therefrigerant tray and containing a refrigerant, the mid shelf positionedwithin the container such that at least some of the plurality of supportknobs are located above the mid shelf and at least some of the pluralityof support knobs are located below the mid shelf; controlling a flow ofair from the container into the refrigerant trays; sublimating therefrigerant to produce a cold gas; regulating a sublimation rate of therefrigerant in response to controlling the flow of air into therefrigerant trays; and passing the cold gas out through the sublimationports and downwardly into a general center of the container interior anddownwardly through the perforations in the mid shelf and through an airgap at each one of the opposing ends of the container between a foodtray and a cart door or end wall of the container and through side gapsformed between each of the one or more food trays and the side walls;and wherein the support knobs, the air gap at each of the opposing ends,the side gaps along the opposing side walls, and the mid shelf cutoutscollectively form a plurality of uninterrupted vertically-oriented flowpaths for the cold gas along the opposing ends and along the side wallsbetween a top and a bottom of the container interior.
 12. The method ofclaim 11 further comprising the steps of: mounting at least one of therefrigerant trays above the food tray; flowing the cold gas generallydownwardly from the sublimation ports; and maintaining the containerinterior below a predetermined temperature.
 13. The method of claim 11further comprising the step of: thermally isolating the refrigerant froma tray lower wall using a thermal isolator installed between therefrigerant and the tray lower wall.
 14. The method of claim 11 furthercomprising the step of: maintaining an air temperature within thecontainer interior at less than approximately 7° C. for a period of atleast approximately 15 hours in an environment having an ambient airtemperature of greater than approximately 29° C.
 15. The containersystem of claim 1 further comprising: an adjustable slider mounted on atleast one of the refrigerant trays and configured to allow for adjustingan area of the vent opening to control the flow of air through the ventopening.
 16. The method of claim 11 further comprising the step of:adjusting a slider mounted on at least one of the refrigerant trays foradjusting an area of the vent opening to control the flow of air intothe refrigerant tray.